Imaging, diagnosis and treatment of disease

ABSTRACT

The present invention relates to endothelial cell-specific genes and encoded polypeptides and materials and uses thereof in the imaging, diagnosis and treatment of conditions involving the vascu lar endothelium.

The present invention relates to genes whose expression is selective forthe endothelium and use of these genes or gene products, or moleculeswhich bind thereto, in imaging, diagnosis and treatment of conditionsinvolving the vascular endothelium.

The endothelium plays a central role in many physiological andpathological processes and it is known to be an exceptionally activetranscriptional site. Approximately 1,000 distinct genes are expressedin an endothelial cell. In contrast red blood cells were found toexpress 8, platelets 22 and smooth muscle 127 separate genes (Adams etal, 1995). Known endothelial specific genes attract much attention fromboth basic research and the clinical community. For example, theendothelial specific tyrosine kinases Tie, TIE2/TEK, KDR, and flt1 arecrucial players in the regulation of vascular integrity,endothelium-mediated inflammatory processes and angiogenesis (Sato etal, 1993, Sato et al, 1995, Fong et al, 1995, Shalaby et al, 1995,Alello et al, 1995). Angiogenesis is now widely recognised as arate-limiting process for the growth of solid tumours. It is alsoimplicated in the formation of atherosclerotic plaques and restenosis.Finally endothelium plays a central role in the complex and dynamicsystem regulating coagulation and hemostasis.

Of the many distinct genes expressed in an endothelial cell, not all areentirely endothelial cell selective and so the genes and their products,and molecules which bind thereto are not generally useful in theimaging, diagnosis and treatment of disease. Thus, there remains a needfor endothelial cell specific or selective molecules.

We report here identification of two highly endothelial selective geneswhich we have called: endothelial cell-specific molecule 1 (ECSM1) andmagic roundabout (endothelial cell-specific molecule 4; ECSM4). Theterms ECSM1 and ECSM4 are also used to indicate, as the context willmake clear, the cDNA and polypeptides encoded by the genes. These genes,and especially ECSM4, are surprisingly specific in their cell expressionprofile. ECSM4, for example, shows similar endothelial-cell selectivityto the marker currently accepted in the art as the best endothelial cellmarker (von Willibrand Factor). Clearly, such a high level ofendothelial cell specificity is both unprecedented and unexpected.

ECSM1 (UniGene entry Hs.13957) has no protein or nucleotide homologues.It is most likely to code for a small protein of 103 aa (the longest andmost up-stream open reading frame which was identified in the contigsequence). ECSM1 contains two sequence tagged sites which are unique anddefinite within the genome (STS sites; dbSTS G26129 and G28043) andlocalise to chromosome 19. A polynucleotide comprising the complement ofpart of the ECSM1 gene is described in WO 99/06423 (Human GenomeSciences) (termed “gene 22”; page 31-32) as being expressed primarily inumbilical cord endothelial cells and to a lesser extent in human adiposetissue. However, WO 99/06423 discloses an open reading frame (ORF) inthe polynucleotide which encodes a polypeptide of only 45 amino acids.According to our analyses, this does not represent the correctpolypeptide of 103 amino acids, as the actual start codon in ECSM 1 isfurther 5′ than the one identified in WO 99/06423.

The human magic roundabout (ECSM4) cDNA clone with a long ORF of morethan 417 aa (GenBank Accession No AK000805) and described in WO 99/46281as a 3716 nucleotide sequence was identified by BLAST searches for theHs.111518 contig. This sequence is rich in prolines and has severalregions of low amino acid complexity. BLAST PRODOM search (proteinfamilies database at HGMP, UK) identified a 120 bp region of homology tothe cytoplasmic domain conserved family of transmembrane receptorsinvolved in repulsive axon guidance (ROBO1 DUTT1 protein family,E=4e-07). Homology was extended to 468 aa (E=1.3e-09) when a morerigorous analysis was performed using search (Smith and Waterman 1981)but the region of similarity was still contained to the cytoplasmicdomain. The ROBO1 DUTT1 family comprises the human roundabout homologue1 (ROBO1), the mouse gene DUTT1 and the rat ROBO1 (Kidd et al, 1998;Brose et al, 1999). Because of this region of homology we called thegene represented by Hs. 111518 “magic roundabout” (ECSM4). Additionally,BLAST SBASE (protein domain database at HGMP) suggested a region ofsimilarity to the domain of the intracellular neural cell adhesionmolecule long domain form precursor (E=2e-11). It should be noted thatthe true protein product for magic roundabout is likely to be largerthan the 417 aa coded in the AK000805 clone since the ORF has noapparent upstream limit, and size comparison to human roundabout 1 (1651aa) suggests a much bigger protein. This is confirmed in FIG. 3 whichshows the translation product of human ECSM4 to be around 118 kDa.However, ECSM4 is smaller than other members of the roundabout family,sharing only two of the five Ig domains and two of the three fibronectindomains in the extracellular region. The intracellular putative prolinerich region that is homologous to those in roundabout are thought tocouple to c-abl. FIG. 12 shows the full length amino acid sequence ofhuman ECSM4 (1105 aa), and the sequence of the mouse homologue is shownin FIG. 13. Nucleotide coding sequences which display around 99%identity to the ECSM4 nucleotide sequence given in FIG. 12 are disclosedin WO 99/11293 and WO 99/53051.

Additional sequences which display homology to the ECSM4 polypeptide orpolynucleotide sequence are disclosed in EP 1 074 617, WO 00/53756, WO99/46281, WO 01/23523 and WO 99/11293. However, none of thesepublications disclose that the sequences are selectively expressed inthe vascular endothelium, nor suggest that they may be so expressed.

Recently intriguing associations between neuronal differentiation genesand endothelial cells have been discovered. For example, a neuronalreceptor for vascular endothelial growth factor (VEGF) neuropilin 1(Soker et al, 1998) was identified. VEGF was traditionally regarded asan exclusively endothelial growth factor. Processes similar to neuronalaxon guidance are now being implicated in guiding migration ofendothelial cells during angiogenic capillary sprouting. Thus ephrinBligands and EphB receptors are involved in demarcation of arterial andvenous domains (Adams et al, 1999). It is possible that magic roundabout(ECSM4) may be an endothelial specific homologue of the human roundabout1 involved in endothelial cell repulsive guidance, presumably with adifferent ligand since similarity is contained within the cytoplasmici.e. effector region and guidance receptors are known to have highlymodular architecture (Bashaw and Goodman 1999).

However, to date there has been no mention of the existence of anendothelial counterpart, nor the expression pattern of the magicroundabout (ECSM4) gene being restricted to endothelial cells especiallyangiogeneic endothelial cells, nor of any function of the encodedpolypeptide.

It should be noted that a surprising result of our RT-PCR analysis,described in Example 1, was that genes identified here appear to showendothelial. specificity (FIG. 1) comparable with the classicendothelial marker von Willebrand factor (vWF). Expression of knownendothelial specific genes is not usually 100% restricted to theendothelial cell. Data presented herein shows the quite unanticipatedfinding that ECSM4 is not expressed at detectable levels (at least usingthe methods described in the examples) in cell types other thanendothelial cells, given the less than 100% selectivity of knownendothelial cell markers. Ribonuclease protection analysis has confirmedand extended this observation (FIG. 14 a). ECSM4 expression was seen tobe restricted to endothelium (three different isolates) and absent fromfibroblast, carcinoma and neuronal cells. KDR and FLT1 are bothexpressed in the male and female reproductive tract: on spermatogeniccells (Obermair et al, 1999), trophoblasts, and in decidua (Clark et al,1996). KDR has been shown to define haematopoietic stem cells (Ziegleret al, 1999). FLT1 is also present on monocytes. In addition toendothelial cells vWF is strongly expressed in megakaryocytes (Spom etal, 1985, Nichols et al, 1985), and in consequence present on platelets.Similarly, multimerin is present both in endothelial cells (Hayward etal, 1993) and platelets (Hayward et al, 1998).

Generally speaking, endothelial and haematopoietic cells descend fromsame embryonic precursors: haemangioblasts and many cellular markers areshared between these two cell lineages (for review see Suda et al,2000). Hence, the finding that the genes ECSM1 and ECSM4 are notexpressed in cells other than those of the vascular endothelium ishighly surprising.

Determination of genes whose expression is selective for the vascularendothelium allows selective targeting to these cells and thereby thespecific delivery of molecules for imaging, diagnosis, prognosis,treatment, prevention and evaluation of therapies for conditionsassociated with normal or aberrant vascular growth.

A first aspect of the invention provides a compound comprising (i) amoiety which selectively binds the polypeptide ECSM4 and (ii) a furthermoiety.

By “the polypeptide ECSM4” we include a polypeptide whose sequencecomprises or consists of the amino acid sequence given in FIGS. 4 or 5or 7 or 12 or 13 or whose sequence is encoded by the nucleotide sequencegiven in FIG. 4 between nucleotides 1 and 1395 or between nucleotides 2and 948 of FIG. 5 or FIG. 7 or between nucleotides 71 and 3442 of FIG.12 or between nucleotides 6 and 3050 of FIG. 13 and natural variantsthereof. Preferably, the ECSM4 polypeptide is one whose amino acidsequence comprises the sequence given in FIG. 4 or FIG. 12.

By “the polypeptide ECSM4” we include a polypeptide represented by SEQID No 18085 of EP 1 074 617, SEQ ID No 211 of either WO 00/53756 orWO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO 01/23523,or SEQ ID No 86 of WO 99/11293, or the polypeptide represented by SEQ IDNo 18084 or 5096 of EP 1 074 617, SEQ ID No 210 of WO 00/53756 or WO99/46281, or SEQ ID Nos 22, 23, 96 or 98 of WO 01/23523 or SEQ ID No 31of WO 99/11293.

By “the polypeptide ECSM4” we also include any naturally occurringpolypeptide which comprises a consecutive 50 amino acid residue portionor natural variants thereof of the polypeptide sequence given in FIG. 4or 5 or 7 or 12 or 13. Preferably, the polypeptide is a humanpolypeptide.

Embodiments and features of this aspect of the invention are asdescribed in more detail below.

A second aspect of the invention provides a compound comprising (i) amoiety which selectively binds the polypeptide ECSM1 and (ii) a furthermoiety.

Preferably, in the first and second aspects of the invention, thebinding moiety and further moiety are covalently attached.

By “the polypeptide ECSM1” we include a polypeptide whose amino acidsequence comprises or consists of the sequence given in FIG. 2 andnatural variants thereof.

By “the polypeptide ECSM1” we also include any naturally occurringpolypeptides which comprises a consecutive 50 amino acid residue portionor natural variants thereof of the polypeptide sequence given in FIG. 2.Preferably, the polypeptide is a human polypeptide.

Preferably, the polypeptide ECSM1 amino acid sequence comprises thesequence given in FIG. 2 but does not comprise the amino acid sequenceencoded by ATCC deposit No 209145 made on Jul. 17 1997 for the purposesof WO 99/06423.

By “natural variants” we include, for example, allelic variants.Typically, these will vary from the given sequence by only one or two orthree, and typically no more than 10 or 20 amino acid residues.Typically, the variants have conservative substitutions.

In a preferred embodiment of the first or second aspects of theinvention, the moiety capable of selectively binding to the specifiedpolypeptide is an antibody.

Preferably, an antibody which selectively binds ECSM1 or a naturalvariant thereof is not one which binds a polypeptide encoded by SEQ IDNo 32 of WO 99/06423 or encoded by the nucleic acid of ATCC deposit No209145 made on Jul. 17 1997 for the purposes of WO 99/06423.

Preferably, an antibody which selectively binds ECSM1 is one which bindsa polypeptide whose amino acid sequence comprises the sequence given inFIG. 2 or a natural variant thereof but which polypeptide does notcomprise the amino acid sequence encoded by ATCC deposit No 209145 madeon Jul. 17 1997.

Preferably, an antibody which selectively binds ECSM4 is one whichselectively binds a polypeptide with the sequence GGDSLLGGRGSL,LLQPPARGHAHDGQALSTDL, EPQDYTEPVE, TAPGGQGAPWAEE or ERATQEPSEHGP or asequence which is located in the extracellular portion of ECSM4. Asdescribed in more detail below, these sequences represent amino acidsequences which are only found in the human ECSM4 and are not found inthe mouse ECSM4 polypeptide sequence.

Preferably, the moiety which selectively binds ECSM4, such as anantibody, is one which binds a polypeptide whose amino acid sequencecomprises the sequence given in any one of FIGS. 4, 5, 7, 12 or 13 or anatural variant thereof but does not bind the polypeptide represented byany one of SEQ ID No 18085 of EP 1 074 617, SEQ ID No 211 of either WO00/53756 or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO01/23523, or SEQ ID No 86 of WO 99/11293, or encoded by any one of thenucleotide sequences represented by SEQ ID No 18084 or 5096 of EP 1 074617, SEQ ID No 210 of WO 00 53756 or WO 99/46281, or SEQ ID Nos 22, 23,96 or 98 of WO 01/23523 and SEQ ID No 31 of WO 99/11293.

By “antibody” we include not only whole immunoglobulin molecules butalso fragments thereof such as Fab, F(ab′)2, Fv and other fragmentsthereof that retain the antigen-binding site. Similarly the term“antibody” includes genetically engineered derivatives of antibodiessuch as single chain Fv molecules (scFv) and domain antibodies (dAbs).The term also includes antibody-like molecules which may be producedusing phage-display techniques or other random selection techniques formolecules which bind to ECSM1 or ECSM4.

The variable heavy (V_(H)) and variable light (V_(L)) domains of theantibody are involved in antigen recognition, a fact first recognised byearly protease digestion experiments. Further confirmation was found by“humanisation” of rodent antibodies. Variable domains of rodent originmay be fused to constant domains of human origin such that the resultantantibody retains the antigenic specificity of the rodent parentedantibody (Morrison et al (1984) Proc. Natl. Acad. Sci. USA81,6851-6855).

That antigenic specificity is conferred by variable domains and isindependent of the constant domains is known from experiments involvingthe bacterial expression of antibody fragments, all containing one ormore variable domains. These molecules include Fab-like molecules(Better et al (1988) Science 240, 1041); Fv molecules (Skerra et al(1988) Science 240, 1038); single-chain Fv (ScFv) molecules where theV_(H) and V_(L) partner domains are linked via a flexible oligopeptide(Bird et al (1988) Science 242,423; Huston et al (1988) Proc. Natl.Acad. Sci. USA 85, 5879) and single domain antibodies (dAbs) comprisingisolated V domains (Ward et al (1989) Nature 341, 544). A general reviewof the techniques involved in the synthesis of antibody fragments whichretain their specific binding sites is to be found in Winter & Milstein(1991) Nature 349, 293-299.

By “ScFv molecules” we mean molecules wherein the V_(H) and V_(L)partner domains are linked via a flexible oligopeptide.

The advantages of using antibody fragments, rather than wholeantibodies, are several-fold. The smaller size of the fragments may leadto improved pharmacological properties, such as better penetration tothe target site. Effector functions of whole antibodies, such ascomplement binding, are removed. Fab, Fv, ScFv and dAb antibodyfragments can all be expressed in and secreted from E. coli, thusallowing the facile production of large amounts of the said fragments.

Whole antibodies, and F(ab′)₂ fragments are “bivalent”. By “bivalent” wemean that the said antibodies and F(ab′)₂ fragments have two antigencombining sites. In contrast, Fab, Fv, ScFv and dAb fragments aremonovalent, having only one antigen combining site.

Although the antibody may be a polyclonal antibody, it is preferred ifit is a monoclonal antibody. In some circumstance, particularly if theantibody is going to be administered repeatedly to a human patient, itis preferred if the monoclonal antibody is a human monoclonal antibodyor a humanised monoclonal antibody.

Suitable monoclonal antibodies which are reactive as said may beprepared by known techniques, for example those disclosed in “MonoclonalAntibodies; A manual of techniques”, H Zola (CRC Press, 1988) and in“Monoclonal Hybridoma Antibodies: Techniques and Application”, SGRHurrell (CRC Press, 1982). Polyclonal antibodies may be produced whichare polypepcific or monospecific. It is preferred that they aremonospecific.

Chimaeric antibodies are discussed by Neuberger et al (1998, 8^(th)International Biotechnology Symposium Part 2, 792-799).

Suitably prepared non-human antibodies can be “humanised” in known ways,for example by inserting the CDR regions of mouse antibodies into theframework of human antibodies.

The antibodies may be human antibodies in the sense that they have theamino acid sequence of human anti-ECSM1 or -ECSM4 antibodies but theymay be prepared using methods known in the art that do not requireimmunisation of humans. For example, transgenic mice are available whichcontain, in essence, human immunoglobulin genes (see Vaughan et al(1998) Nature Biotechnol. 16, 535-539.

In an alternative embodiment, the moiety capable of selectively bindingto a polypeptide is a peptide. The ECSM4/magic roundabout polypeptideshows homology with the Drosophila, mouse and human roundabout proteins,which are cell surface receptors for secreted Slit proteins (Li et al(1996) Cell 96:807-818). Any cognate ligand for ECSM4/magic roundaboutwhich is capable of selectively binding the region of the polypeptidewhich is located extracellularly may be useful. The extracellular regionof ECSM4 is likely to be located within residues 1-467 of the ECSM4polypeptide sequence given in FIG. 12. It is believed that certainpeptides may be cognate ligands for ECSM4. Such a peptide will be asuitable moiety for selectively binding ECSM4/magic roundabout. Peptidesbinding ECSM4 can be identified by means of a screen. A suitable methodor screen for identifying peptides or other molecules which selectivelybind ECSM4 may comprise contacting the ECSM4 polypeptide with a testpeptide or other molecule under conditions where binding can occur, andthen determining if the test molecule or peptide has bound ECSM4.Methods of detecting binding between two moieties are well known in theart of biochemistry. Preferably, the known technique of phage display isused to identify peptides or other ligand molecules which bind to ECSM4.An alternative method includes the yeast two hybrid system.

Peptides or other agents which selectively bind ECSM4 include thosewhich modulate or block the function of ECSM4.

Suitable peptides may be synthesised as described in more detail below.

The further moiety may be any further moiety which confers on thecompound a useful property with respect to the treatment or imaging ordiagnosis of diseases or other conditions or states which involveundesirable neovasculature formation. Such diseases or other conditionsor states are described in more detail below. In particular, the furthermoiety is one which is useful in killing or imaging neovasculatureassociated with the growth of a tumour. Preferably, the further moietyis one which is able to kill the endothelial cells to which the compoundis targeted.

In a preferred embodiment of the invention the further moiety isdirectly or indirectly cytotoxic. In particular the further moiety ispreferably directly or indirectly toxic to cells in neovasculature orcells which are in close proximity to and associated withneovasculature.

By “directly cytotoxic” we include the meaning that the moiety is onewhich on its own is cytotoxic. By “indirectly cytotoxic” we include themeaning that the moiety is one which, although is not itself cytotoxic,can induce cytotoxicity, for example by its action on a further moleculeor by further action on it

In one embodiment the cytotoxic moiety is a cytotoxic chemotherapeuticagent. Cytotoxic chemotherapeutic agents are well known in the art.

Cytotoxic chemotherapeutic agents, such as anticancer agents, include:alkylating agents including nitrogen mustards such as mechlorethamine(HN₂), cyclophosphamide, ifosfamide, melphalan (L-sarcolysin) andchlorambucil; ethylenimines and methylmelamines such ashexamethylmelamine, thiotepa; alkyl sulphonates such as busulfan;nitrosoureas such as carmustine (BCNU), lomustine (CCNU), semustine(methyl-CCNU) and streptozocin (streptozotocin); and triazenes such asdecarbazine (DTIC; dimethyltriazenoimidazole-carboxamide);Antimetabolites including folic acid analogues such as methotrexate(amethopterin); pyrimidine analogues such as fluorouracil(5-fluorouracil; 5-FU), floxuridine (fluorodeoxyuridine; FUdR) andcytarabine (cytosine arabinoside); and purine analogues and relatedinhibitors such as mercaptopurine (6-mercaptopurine; 6-MP), thioguanine(6-thioguanine; TG) and pentostatin (2′-deoxycoformycin). NaturalProducts including vinca alkaloids such as vinblastine (VLB) andvincristine; epipodophyllotoxins such as etoposide and teniposide;antibiotics such as dactinomycin (actinomycin D), daunorubicin(daunomycin; rubidomycin), doxorubicin, bleomycin, plicamycin(mithramycin) and mitomycin (mitomycin C); enzymes such asL-asparaginase; and biological response modifiers such as interferonalphenomes. Miscellaneous agents including platinum coordinationcomplexes such as cisplatin (cis-DDP) and carboplatin; anthracenedionesuch as mitoxantrone and anthracycline; substituted urea such ashydroxyurea; methyl hydrazine derivative such as procarbazine(N-methylhydrazine, MIH); and adrenocortical suppressant such asmitotane (o,p′-DDD) and aminoglutethimide; taxol andanalogues/derivatives; and hormone agonists/antagonists such asflutamide and tamoxifen.

Various of these agents have previously been attached to antibodies andother target site-delivery agents, and so compounds of the inventioncomprising these agents may readily be made by the person skilled in theart. For example, carbodiimide conjugation (Bauminger & Wilchek (1980)Methods Enzymol. 70, 151-159; incorporated herein by reference) may beused to conjugate a variety of agents, including doxorubicin, toantibodies or peptides.

Carbodiimides comprise a group of compounds that have the generalformula R—N═C═N—R′, where R and R′ can be aliphatic or aromatic, and areused for synthesis of peptide bonds. The preparative procedure issimple, relatively fast, and is carried out under mild conditions.Carbodiimide compounds attack carboxylic groups to change them intoreactive sites for free amino groups.

The water soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) is particularly useful for conjugating a functionalmoiety to a binding moiety and may be used to conjugate doxorubicin totumor homing peptides. The conjugation of doxorubicin and a bindingmoiety requires the presence of an amino group, which is provided bydoxorubicin, and a carboxyl group, which is provided by the bindingmoiety such as an antibody or peptide.

In addition to using carbodiimides for the direct formation of peptidebonds, EDC also can be used to prepare active esters such asN-hydroxysuccinimide (NHS) ester. The NHS ester, which binds only toamino groups, then can be used to induce the formation of an amide bondwith the single amino group of the doxorubicin. The use of EDC and NHSin combination is commonly used for conjugation in order to increaseyield of conjugate formation (13 auminger & Wilchek, supra, 1980).

Other methods for conjugating a functional moiety to a binding moietyalso can be used. For example, sodium periodate oxidation followed byreductive alkylation of appropriate reactants can be used, as canglutaraldehyde cross-linking. However, it is recognised that, regardlessof which method of producing a conjugate of the invention is selected, adetermination must be made that the binding moiety maintains itstargeting ability and that the functional moiety maintains its relevantfunction.

In a further embodiment of the invention, the cytotoxic moiety is acytotoxic peptide or polypeptide moiety by which we include any moietywhich leads to cell death. Cytotoxic peptide and polypeptide moietiesare well known in the art and include, for example, ricin, abrin,Pseudomonas exotoxin, tissue factor and the like. Methods for linkingthem to targeting moieties such as antibodies are also known in the art.The use of ricin as a cytotoxic agent is described in Burrows & Thorpe(1993) Proc. Natl. Acad. Sci. USA 90, 8996-9000, incorporated herein byreference, and the use of tissue factor, which leads to localised bloodclotting and infarction of a tumour, has been described by Ran et al(1998) Cancer Res. 58, 4646-4653 and Huang et al (1997) Science 275,547-550. Tsai et al (1995) Dis. Colon Rectum 38, 1067-1074 describes theabrin A chain conjugated to a monoclonal antibody and is incorporatedherein by reference. Other ribosome inactivating proteins are describedas cytotoxic agents in WO 96/06641. Pseudomonas exotoxin may also beused as the cytotoxic polypeptide moiety (see, for example, Aiello et al(1995) Proc. Natl. Acad. Sci. USA 92, 10457-10461; incorporated hereinby reference).

Certain cytokines, such as TNFα and IL-2, may also be useful ascytotoxic agents.

Certain radioactive atoms may also be cytotoxic if delivered insufficient doses. Thus, the cytotoxic moiety may comprise a radioactiveatom which, in use, delivers a sufficient quantity of radioactivity tothe target site so as to be cytotoxic. Suitable radioactive atomsinclude phosphorus-32, iodine-125, iodine-131, indium-111, rhenium-186,rhenium-188 or yttrium-90, or any other isotope which emits enoughenergy to destroy neighbouring cells, organelles or nucleic acid.Preferably, the isotopes and density of radioactive atoms in thecompound of the invention are such that a dose of more than 4000 cGy(preferably at least 6000, 8000 or 10000 cGy) is delivered to the targetsite and, preferably, to the cells at the target site and theirorganelles, particularly the nucleus.

The radioactive atom may be attached to the binding moiety in knownways. For example EDTA or another chelating agent may be attached to thebinding moiety and used to attach ¹¹¹In or ⁹⁰Y: Tyrosine residues may belabelled with ¹²⁵I or ¹³¹I.

The cytotoxic moiety may be a suitable indirectly cytotoxic polypeptide.In a particularly preferred embodiment, the indirectly cytotoxicpolypeptide is a polypeptide which has enzymatic activity and canconvert a relatively non-toxic prodrug into a cytotoxic drug. When thetargeting moiety is an antibody this type of system is often referred toas ADEPT (Antibody-Directed Enzyme Prodrug Therapy). The system requiresthat the .targeting moiety locates the enzymatic portion to the desiredsite in the body of the patient (ie the site expressing ECSM1 or ECSM4,such as new vascular tissue associated with a tumour) and after allowingtime for the enzyme to localise at the site, administering a prodrugwhich is a substrate for the enzyme, the end product of the catalysisbeing a cytotoxic compound. The object of the approach is to maximisethe concentration of drug at the desired site and to minimise theconcentration of drug in normal tissues (see Senter, P. D. et al (1988)“Anti-tumor effects of antibody-alkaline phosphatase conjugates incombination with etoposide phosphate” Proc. Natl. Acad. Sci. USA 85,4842-4846; Bagshawe (1987) Br. J Cancer 56, 531-2; and Bagshawe, K. D.et al (1988) “A cytotoxic agent can be generated selectively at cancersites” Br. J Cancer. 58, 700-703.)

Clearly, any ECSM1 or ECSM4 binding moiety may be used in place of ananti-ECSM1 or anti-ECSM4 antibody in this type of directed enzymeprodrug therapy system.

The enzyme and prodrug of the system using an ECSM1 or ECSM4 targetedenzyme as described herein may be any of those previously proposed. Thecytotoxic substance may be any existing anti-cancer drug such as analkylating agent; an agent which intercalates in DNA; an agent whichinhibits any key enzymes such as dihydrofolate reductase, thymidinesynthetase, ribonucleotide reductase, nucleoside kinases ortopoisomerase; or an agent which effects cell death by interacting withany other cellular constituent. Etoposide is an example of atopoisomerase inhibitor.

Reported prodrug systems include: a phenol mustard prodrug activated byan E. coli β-glucuronidase (Wang et al, 1992 and Roffler et al, 1991); adoxorubicin prodrug activated by a human β-glucuronidase (Bosslet et al,1994); further doxorubicin prodrugs activated by coffee beanα-galactosidase (Azoulay et al, 1995); daunorubicin prodrugs, activatedby coffee bean α-D-galactosidase (Gesson et al, 1994); a 5-fluorouridineprodrug activated by an E. coli β-D-galactosidase (Abraham et al, 1994);and methotrexate prodrugs (eg methotrexate-alanine) activated bycarboxypeptidase A (Kuefier et al, 1990, Vitols et al, 1992 and Vitolset al, 1995). These and others are included in the following table.

Enzyme Prodrug Carboxypeptidase G2 Derivatives of L-glutamic acid andbenzoic acid mustards, aniline mustards, phenol mustards andphenylenediamine mustards; fluorinated derivatives of these Alkalinephosphatase Etoposide phosphate Mitomycin phosphate Beta-glucuronidasep-Hydroxyaniline mustard-glucuronide Epirubicin-glucuronidePenicillin-V-amidase Adriamycin-N phenoxyacetyl Penicillin-G-amidaseN-(4′-hydroxyphenyl acetyl) palytoxin Doxorubicin and melphalanBeta-lactamase Nitrogen mustard-cephalosporin p-phenylenediamine;doxorubicin derivatives; vinblastine derivative-cephalosporin,cephalosporin mustard; a taxol derivative Beta-glucosidaseCyanophenylmethyl-beta-D-gluco- pyranosiduronic acid Nitroreductase5-(Azaridin-1-yl-)-2,4-dinitrobenzamide Cytosine deaminase5-Fluorocytosine Carboxypeptidase A Methotrexate-alanine(This table is adapted from Bagshawe (1995) Drug Dev. Res. 34, 220-230,from which full references for these various systems may be obtained;the taxol derivative is described in Rodrigues, M. L. et al (1995)Chemistry & Biology 2, 223).

Suitable enzymes for forming part of the enzymatic portion of theinvention include: exopeptidases, such as carboxypeptidases G, G1 and G2(for glutamylated mustard prodrugs), carboxypeptidases A and B (forMTX-based prodrugs) and aminopeptidases (for 2-α-aminocyl MTC prodrugs);endopeptidases, such as eg thrombolysin (for thrombin prodrugs);hydrolases, such as phosphatases (eg alkaline phosphatase) orsulphatases (eg aryl sulphatases) (for phosphylated or sulphatedprodrugs); amidases, such as penicillin amidases and arylacyl amidase;lactamases, such as β-lactamases; glycosidases, such as β-glucuronidase(for β-glucuronomide anthracyclines), α-galactosidase (for amygdalin)and β-galactosidase (for β-galactose anthracycline); deaminases, such ascytosine deaminase (for 5FC); kinases, such as urokinase and thymidinekinase (for gancyclovir); reductases, such as nitroreductase (for CB1954and analogues), azoreductase (for azobenzene mustards) and DT-diaphorase(for CB1954); oxidases, such as glucose oxidase (for glucose), xanthineoxidase (for xanthine) and lactoperoxidase; DL-racemases, catalyticantibodies and cyclodextrins.

The prodrug is relatively non-toxic compared to the cytotoxic drug.Typically, it has less than 10% of the toxicity, preferably less than 1%of the toxicity as measured in a suitable in vitro cytotoxicity test.

It is likely that the moiety which is able to convert a prodrug to acytotoxic drug will be active in isolation from the rest of the compoundbut it is necessary only for it to be active when (a) it is incombination with the rest of the compound and (b) the compound isattached to, adjacent to or intemalised in target cells.

When each moiety of the compound is a polypeptide, the two portions maybe linked together by any of the conventional ways of cross-linkingpolypeptides, such as those generally descnbed in O'Sullivan et al(1979) Anal. Biochem. 100, 100-108. For example, the ECSM1 or ECSM4binding moiety may be enriched with thiol groups and the further moietyreacted with a bifunctional agent capable of reacting with those thiolgroups, for example the N-hydroxysuccinimide ester of iodoacetic acid(NHIA) or N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP). Amide andthioether bonds, for example achieved withm-maleimidobenzoyl-N-hydroxysuccininide ester, are generally more stablein vivo than disulphide bonds.

Alternatively, the compound may be produced as a fusion compound byrecombinant DNA techniques whereby a length of DNA comprises respectiveregions encoding the two moieties of the compound of the inventioneither adjacent one another or separated by a region encoding a linkerpeptide which does not destroy the desired properties of the compound.Conceivably, the two portions of the compound may overlap wholly orpartly.

The DNA is then expressed in a suitable host to produce a polypeptidecomprising the compound of the invention.

The invention also provides a kit of parts (or a therapeutic system)comprising (1) a compound of the invention wherein the further moietywhich is able to convert a relatively non-toxic prodrug into a cytotoxicdrug and (2) a relatively non-toxic prodrug. The kit of parts maycomprise any of the compounds of the invention and appropriate prodrugsas herein disclosed.

The invention also provides a kit of parts (or a therapeutic system)comprising (i) a compound of the invention wherein the further moiety isable to bind selectively to a directly or indirectly cytotoxic moiety orto a readily detectable moiety and (2) any one of a directly orindirectly cytotoxic or a readily detectable moiety to which the furthermoiety of the compound is able to bind.

The cytotoxic moiety may be a radiosensitizer. Radiosensitizers includefluoropyrimidines, thymidine analogues, hydroxyurea, gemcitabine,fludarabine, nicotinamide, halogenated pyrimidines, 3-aminobenzamide,3-aminobenzodiamide, etanixadole, pimonidazole and misonidazole (see,for example, McGinn et al (1996) J. Natl. Cancer Inst. 88, 1193-11203;Shewach & Lawrence (1996) Invest. New Drugs 14, 257-263; Horsman (1995)Acta Oncol. 34, 571-587; Shenoy & Singh (1992) Clin. Invest. 10,533-551; Mitchell et al (1989) Int. J Radiat. Biol. 56, 827-836; Iliakis& Kurtzman (1989) Int. J Radiat. Oncol. Biol. Phys. 16, 1235-1241; Brown(1989) Int. J. Radiat. Oncol. Biol. Phys. 16, 987-993; Brown (1985)Cancer 55, 2222-2228).

Also, delivery of genes into cells can radiosensitise them, for exampledelivery of the p53 gene or cyclin D (Lang et al (1998) J. Neurosurg.89, 125-132; Coco Martin et al (1999) Cancer Res. 59, 1134-1140).

The further moiety may be one which becomes cytotoxic, or releases acytotoxic moiety, upon irradiation. For example, the boron-10 isotope,when appropriately irradiated, releases a particles which are cytotoxic(see for example, U.S. Pat. No. 4,348,376 to Goldenberg; Primus et al(1996) Bioconjug. Chem. 7, 532-535).

Similarly, the cytotoxic moiety may be one which is useful inphotodynamic therapy such as photofrin (see, for example, Dougherty etal (1998) J. Natl. Cancer Inst. 90, 889-905).

The further moiety may comprise a nucleic acid molecule which isdirectly or indirectly cytotoxic. For example, the nucleic acid moleculemay be an antisense oligonucleotide which, upon localisation at thetarget site is able to enter cells and lead to their death. Theoligonucleotide, therefore, may be one which prevents expression of anessential gene, or one which leads to a change in gene expression whichcauses apoptosis.

Examples of suitable oligonucleotides include those directed at bcl-2(Ziegler et al (1997) J. Natl. Cancer Inst. 89, 1027-1036), and DNApolymerase α and topoisomerase IIα (Lee et al (1996) Anticancer Res. 16,1805-1811.

Peptide nucleic acids may be useful in place of conventional nucleicacids (see Knudsen & Nielsen (1997) Anticancer Drugs 8, 113-118).

In a further embodiment, the binding moiety may be comprised in adelivery vehicle for delivering nucleic acid to the target. The deliveryvehicle may be any suitable delivery vehicle. It may, for example, be aliposome containing nucleic acid, or it may be a virus or virus-likeparticle which is able to deliver nucleic acid. In these cases, themoiety which selectively binds to ECSM1 or ECSM4 is typically present onthe surface of the delivery vehicle. For example, the moiety whichselectively binds to ECSM1 or ECSM4, such as a s suitable antibodyfragment, may be present in the outer surface of a liposome and thenucleic acid to be delivered may be present in the interior of theliposome. As another example, a viral vector, such as a retroviral oradenoviral vector, is engineered so that the moiety which selectivelybinds to ECSM1 or ECSM4 is attached to or located in the surface of theviral particle thus enabling the viral particle to be targeted to thedesired site. Targeted delivery systems are also known such as themodified adenovirus system described in WO 94/10323 wherein, typically,the DNA is carried within the adenovirus, or adenovirus-like, particle.Michael et al (1995) Gene Therapy 2, 660-668 describes modification ofadenovirus to add a cell-selective moiety into a fibre protein. Targetedretroviruses are also available for use in the invention; for example,sequences conferring specific binding affinities may be engineered intopreexisting viral env genes (see Miller & Vile (1995) Faseb J. 9,190-199 for a review of this and other targeted vectors for genetherapy).

Immunoliposomes (antibody-directed liposomes) may be used in which themoiety which selectively binds to ECSM1 or ECSM4 is an antibody. For thepreparation of immuno-liposomes MPB-PE(N-[4-(p-maleimidophenyl)butyryl]-phosphatidylethanolamine) issynthesised according to the method of Martin & Papahadjopoulos (1982)J. Biol. Chem. 257, 286-288. MPB-PE is incorporated into the liposomalbilayers to allow a covalent coupling of the anti-ECSM1 or -ECSM4antibody, or fragment thereof, to the liposomal surface. The liposome isconveniently loaded with the DNA or other genetic construct for deliveryto the target cells, for example, by forming the said liposomes in asolution of the DNA or other genetic construct, followed by sequentialextrusion through polycarbonate membrane filters with 0.6 μm and 0.2 μmpore size under nitrogen pressures up to 0.8 MPa. After extrusion,entrapped DNA construct is separated from free DNA construct byultracentrifugation at 80 000×g for 45 min. Freshly preparedMPB-PE-liposomes in deoxygenated buffer are mixed with freshly preparedantibody (or fragment thereof) and the coupling reactions are carriedout in a nitrogen atmosphere at 4° C. under constant end over endrotation overnight. The immunoliposomes are separated from unconjugatedantibodies by ultracentrifugation at 80 000×g for 45 min.Immunoliposomes may be injected intraperitoneally or directly into thetumour.

The nucleic acid delivered to the target site may be any suitable DNAwhich leads, directly or indirectly, to cytotoxicity. For example, thenucleic acid may encode a ribozyme which is cytotoxic to the cell, or itmay encode an enzyme which is able to convert a substantially non-toxicprodrug into a cytotoxic drug (this latter system is sometime calledGDEPT: Gene Directed Enzyme Prodrug Therapy).

Ribozymes which may be encoded in the nucleic acid to be delivered tothe target are described in Cech and Herschlag “Site-specific cleavageof single stranded DNA” U.S. Pat. No. 5,180,818; Altman et al “Cleavageof targeted RNA by RNAse P” U.S. Pat. No. 5,168,053, Cantin et al“Ribozyme cleavage of HIV-1 RNA” U.S. Pat. No. 5,149,796; Cech et al“RNA ribozyme restriction endoribonucleases and methods”, U.S. Pat. No.5,116,742; Been et al “RNA ribozyme polymerases, dephosphorylases,restriction endonucleases and methods”, U.S. Pat. No. 5,093,246; andBeen et al “RNA ribozyme polymerases, dephosphorylases, restrictionendoribonucleases and methods; cleaves single-stranded RNA at specificsite by transesterification”, U.S. Pat. No. 4,987,071, all incorporatedherein by reference. Suitable targets for ribozymes includetranscription factors such as c-fos and c-myc, and bcl-2. Durai et al(1997) Anticancer Res. 17, 3307-3312 describes a hammerhead ribozymeagainst bcl-2.

EP 0 415 731 describes the GDEPT system. Similar considerationsconcerning the choice of enzyme and prodrug apply tomte GDEPT system asto the ADEPT system described above.

The nucleic acid delivered to the target site may encode a directlycytotoxic polypeptide.

Alternatively, the further portion may comprise a polypeptide or apolynucleotide encoding a polypeptide which is not either directly orindirectly cytotoxic but is of therapeutic benefit. Examples of suchpolypeptides include anti-proliferative or anti-inflammatory cytokineswhich could be of benefit in artherosclerosis, and anti-proliferative,immunomodulatory or factors influencing blood clotting may be of benefitin treating cancer.

The further moiety may usefully be an inhibitor of angiogenesis such asthe peptides angiostatin or endostatin. The further moiety may alsousefully be an enzyme which converts a precursor polypeptide toangiostatin or endostatin. Human matrix metallo-proteases such asmacrophage elastase, gelatinase and stromolysin convert plasminogen toangiostatin (Cornelius et al (1998) J. Immunol. 161, 6845-6852).Plasminogen is a precursor of angiostatin.

In a further embodiment of the invention, the further moiety comprisedin the compound of the invention is a readily detectable moiety.

By a “readily detectable moiety” we include the meaning that the moietyis one which, when located at the target site following administrationof the compound of the invention into a patient, may be detected,typically non-invasively from outside the body and the site of thetarget located. Thus, the compounds of this embodiment of the inventionare useful in imaging and diagnosis.

Typically, the readily detectable moiety is or comprises a radioactiveatom which is useful in imaging. Suitable radioactive atoms includetechnetium-99m or iodine-123 for scintigraphic studies. Other readilydetectable moieties include, for example, spin labels for magneticresonance imaging (MRI) such as iodine-123 again, iodine-131,indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17, gadolinium,manganese or iron. Clearly, the compound of the invention must havesufficient of the appropriate atomic isotopes in order for the moleculeto be readily detectable.

The radio- or other labels may be incorporated in the compound of theinvention in known ways. For example, if the binding moiety is apolypeptide it may be biosynthesised or may be synthesised by chemicalamino acid synthesis using suitable amino acid precursors involving, forexample, fluorine-l 9 in place of hydrogen. Labels such as ^(99m)Tc,¹²³I, ¹⁸⁶Rh, ¹⁸⁸Rh and ¹¹¹In can, for example, be attached via cysteineresidues in the binding moiety. Yttrium-90 can be attached via a lysineresidue. The IODOGEN method (Fraker er al (1978) Biochem. Biophys. Res.Comm. 80, 49-57) can be used to incorporate iodine-123. Reference(“Monoclonal Antibodies in Immunoscintigraphy”, J-F Chatal, CRC Press,1989) describes other methods in detail.

In a further preferred embodiment of the invention the further moiety isable to bind selectively to a directly or indirectly cytotoxic moiety orto a readily detectable moiety. Thus, in this embodiment, the furthermoiety may be any moiety which binds to a further compound or componentwhich is cytotoxic or readily detectable.

The further moiety may, therefore be an antibody which selectively bindsto the further compound or component, or it may be some other bindingmoiety such as streptavidin or biotin or the like. The followingexamples illustrate the types of molecules that are included in theinvention; other such molecules are readily apparent from the teachingsherein.

A bispecific antibody wherein one binding site comprises the moietywhich selectively binds to ECSM1 or ECSM4 and the second binding sitecomprises a moiety which binds to, for example, an enzyme which is ableto convert a substantially non-toxic prodrug to a cytotoxic drug.

A compound, such as an antibody which selectively binds to ECSM1 orECSM4, to which is bound biotin. Avidin or streptavidin which has beenlabelled with a readily detectable label may be used in conjunction withthe biotin labelled antibody in a two-phase imaging system wherein thebiotin labelled antibody is first localised to the target site in thepatient, and then the labelled avidin or streptavidin is administered tothe patient. Bispecific anti-bodies and biotin/streptavidin (avidin)systems are reviewed by Rosebrough (1996) Q J Nucl. Med. 40, 234-251.

In a preferred embodiment of the invention, the moiety which selectivelybinds to ECSM1 or ECSM4 and the further moiety are polypeptides whichare fused.

The compounds of the first and second aspects of the invention areuseful in treating, imaging or diagnosing disease, particularly diseasesin which there may be undesirable neovasculature formation, as describedin more detail below.

In a preferred embodiment of the first and second aspects of theinvention, the compounds are suitable for use in medicine.

A third aspect of the invention provides a nucleic acid moleculeencoding a compound of either the first or second aspects of theinvention wherein the selective binding moiety and the further moietyare polypeptides which are fused.

Methods of linking polynucleotides are described in more detail below.

A fourth aspect of the invention provides a pharmaceutical compositioncomprising a compound according to the invention and a pharmaceuticallyacceptable carrier. The compound of the invention includes thosedescribed in the first, second and third aspects. The invention alsoincludes pharmaceutical composition comprising any of an antibody,polypeptide, peptide, polynucleotide, expression vector or other agentwhich may be delivered to an individual as described below and apharmaceutically acceptable carrier.

By “pharmaceutically acceptable” is included that the formulation issterile and pyrogen free. Suitable pharmaceutical carriers are wellknown in the art of pharmacy.

The carrier(s) must be “acceptable” in the sense of being compatiblewith the compound of the invention and not deleterious to the recipientsthereof. Typically, the carriers will be water or saline which will besterile and pyrogen free; however, other acceptable carriers may beused.

Typically the pharmaceutical compositions or formulations of theinvention are for parenteral administration, more particularly forintravenous administration.

Formulations suitable for parenteral administration include aqueous andnon-aqueous sterile injection solutions which may contain anti-oxidants,buffers, bacteriostats and solutes which render the formulation isotonicwith the blood of the intended recipient; and aqueous and non-aqueoussterile suspensions which may include suspending agents and thickeningagents.

A fifth aspect of the invention provides a method of imaging vascularendothelium in the body of an individual the method comprisingadministering to the individual an effective amount of a compoundaccording to either of the first or second aspects of the inventionwherein the further moiety is a readily detectable moiety.

Typically the vascular endothelium is associated with angiogenesis.

As discussed above in relation to the first and second aspects of theinvention, the moiety of the compound which selectively binds ECSM4 orECSM1 may be an antibody. Preferred antibodies are as outlined above.

In a preferred embodiment of this aspect of the invention, the method ofimaging the vascular endothelium in an individual comprises the furtherstep of detecting the location of the compound in the individual.

Detecting the compound or antibody can be achieved using methods wellknown in the art of clinical imaging and diagnostics. The specificmethod required will depend on the type of detectable label attached tothe compound or antibody. For example, radioactive atoms may be detectedusing autoradiography or in some cases by magnetic resonance imaging(MRI) as described above.

Imaging the vascular endothelium in the body is useful because it canprovide information about the health of the body. It is particularlyuseful when the vascular endothelium is diseased, or is proliferatingdue to a cancerous growth. Imaging cancer in a patient is especiallyuseful, because it can be used to determine the size of a tumour andwhether it is responding to treatment. Since metastatic disease involvesnew blood vessel formation, the method is useful in assessing whethermetastasis has occurred.

Hence, in a preferred embodiment of the fifth aspect of the invention,the vascular endothelium is neovasculature, such as that produced incancer.

A sixth aspect of the invention provides a method of diagnosing orprognosing in an individual a condition which involves the vascularendothelium the method comprising administering to the individual aneffective amount of a compound according to either of the first orsecond aspects of the invention wherein the further moiety is a readilydetectable moiety.

The condition may be one which involves aberrant or excessive growth ofvascular endothelium, such as cancer, artheresclerosis, restenosis,diabetic retinopathy, arthritis, psoriasis, endometriosis, menorrhagia,haemangiomas and venous malformations.

As discussed in relation to the first and second aspects of theinvention, the compound may comprise an antibody. The antibody may beany antibody which selectively binds the polypeptide ECSM1 or ECSM4 asrequired. Preferred antibodies which bind the polypeptide ECSM4 are asoutlined above.

The method may be one which is an aid to diagnosis.

In a preferred embodiment of this aspect of the invention, the method ofdiagnosing, or aiding diagnosis of, a condition involving the vascularendothelium in an individual comprises the further step of detecting thelocation of the compound in the individual. Preferably the endotheliumis in neovasculature; ie, angiogenic vasculature.

The function of ECSM4 or ECSM1 may not be to promote proliferation ofvascular endothelial cells. Therefore the level of expression of thesepolypeptides within an endothelial cell may not be informative about thehealth of the vascular endothelium. However, the location of expressionof the polypeptides may be informative, as they represent the growth ofblood vessels. Abnormal cell proliferation such as cancer may bediagnosed by the detection of new vasculature.

A seventh aspect of the invention provides a method of treating anindividual in need of treatment, the method comprising administering tothe individual an effective amount of a compound according to the firstor second aspects of the invention wherein the further moiety is acytotoxic or therapeutic moiety.

In one embodiment of this aspect, the patient in need of treatment has aproliferative disease or a condition involving the vascular endothelium.

A number of diseases and conditions involve undesirable neovasculatureformation. Neovasculature formation is associated with cancer,psoriasis, atherosclerosis, menorrhagia, arthritis (both inflammatoryand rheumatoid), macular degeneration, Paget's disease, retinopathy andits vascular complications (including proliferative and of prematurity,and diabetic), benign vascular proliferations and fibroses.

By cancer is included Kaposi's sarcoma, leukaemia, lymphoma, myeloma,solid carcinomas (both primary and secondary (metastasis), vasculartumours including haemangioma (both capillary and juvenile (infantile)),haemangiomatosis and haemagioblastoma.

Thus, the invention comprises a method of treating a patient who has adisease in which angiogenesis contributes to pathology the methodcomprising the step of administering to the patient an effective amountof a compound of the first or second aspect of the invention wherein thefurther moiety of the compound is one which either directly orindirectly is of therapeutic benefit to the patient.

Typically, the disease is associated with undesirable neovasculatureformation and the treatment reduces this to a useful extent.

The tumours that may be treated by the methods of the invention includeany tumours which are associated with new blood vessel production.

The term “tumour” is to be understood as referring to all forms ofneoplastic cell growth, including tumours of the lung, liver, bloodcells, skin, pancreas, stomach, colon, prostate, uterus, breast, lymphglands and bladder. Solid tumours are especially suitable. However,blood cancers, including leukaemias and lymphomas are now also believedto involve new blood vessel formation and may be treated by the methodsof the invention.

Typically in the above-mentioned methods of treatment, the furthermoiety is one which destroys or slows or reverses the growth of theneovasculature.

It will readily be appreciated that, depending on the particularcompound used in imaging, diagnosis or treatment, the timing ofadministration may vary and the number of other components used intherapeutic systems disclosed herein may vary.

For example, in the case where the compound of the invention comprises areadily detectable moiety or a directly cytotoxic moiety, it may be thatonly the compound, in a suitable formulation, is administered to thepatient. Of course, other agents such as immunosuppressive agents andthe like may be administered.

In respect of compounds which are detectably labelled, imaging takesplace once the compound has localised at the target site.

However, if the compound is one which requires a further component inorder to be useful for treatment, imaging or diagnosis, the compound ofthe invention may be administered and allowed to localise at the targetsite, and then the further component administered at a suitable timethereafter.

For example, in respect of the ADEPT and ADEPT-like systems above, thebinding moiety-enzyme moiety compound is administered and localises tothe target site. Once this is done, the prodrug is administered.

Similarly, for example, in respect of the compounds wherein the furthermoiety comprised in the compound is one which binds a further component,the compound may be administered first and allowed to localise at thetarget site, and subsequently the further component is administered.

Thus, in one embodiment a biotin-labelled anti-ECSM1 or -ECSM4 antibodyis administered to the patient and, after a suitable period of time,detectably labelled streptavidin is administered. Once the streptavidinhas localised to the sites where the antibody has localised (ie thetarget sites) imaging takes place.

Where the compound whose moiety which selectively binds is an antibody,the antibody may be any antibody which selectively binds the polypeptideECSM1 or ECSM4 as required. Preferred antibodies are as outlined in thefirst and second aspects of the invention.

It is believed that the compounds of the invention wherein the furthermoiety is a readily detectable moiety may be useful in determining theangiogenic status of tumours or other disease states in whichangiogenesis contributes to pathology. This may be an important factorinfluencing the nature and outcome of future therapy.

An eighth aspect of the invention provides a method of introducinggenetic material selectively into vascular endothelial cells the methodcomprising contacting the cells with a compound according to either ofthe first or second aspects of the invention as described above whereinthe further moiety is a nucleic acid.

The vascular endothelial cells may be any vascular endothelial cellssuch as those in tissue culture or in a living organism. It is preferredif the cells are in a living organism. It is further preferred if theorganism is a human. It is still more preferred if the vascularendothelial cells are those in neovasculature, ie they are angiogenicendothelial cells.

Preferably, the binding moiety is an antibody. The antibody may be anyantibody which selectively binds the polypeptide ECSM1 or ECSM4 asrequired. Preferably, the antibody is one as defined above in relationto the first or second aspects of the invention. Typically, the bindingmoiety is comprised in a delivery vehicle and preferably, the deliveryvehicle is a liposome, as described in further detail above. In thisembodiment, the further moiety is nucleic acid and is comprised withinthe liposome, also as described above. Typically, the method is used ingene therapy, and the genetic material is therapeutically useful.Therapeutically useful genetic material includes that which encodes atherapeutic protein.

A ninth aspect of the invention provides a use of a compound accordingto either of the first or second aspects of the invention wherein thefurther moiety is a readily detectable label in the manufacture of adiagnostic or prognostic agent for a condition which involves thevascular endothelium.

As discussed above, the compound may comprise an antibody as the moietywhich selectively binds. The antibody may be any antibody whichselectively binds the polypeptide ECSM1 or ECSM4 as required.

A tenth aspect of the invention provides a use of a compound accordingto either of the first or second aspects of the invention wherein thefurther moiety is a cytotoxic or therapeutic moiety in the manufactureof a medicament for treating a condition involving the vascularendothelium.

Conditions which involve the vascular endothelium are described above.

As described above, the compound may comprise an antibody as the moietywhich selectively binds. The antibody may be any suitable antibody whichselectively binds the polypeptide ECSM1 or ECSM4 as required.

An eleventh aspect of the invention provides a polypeptide comprising orconsisting of a fragment or variant or fusion of the ECSM4 polypeptideor a fusion of said fragment or variant provided that it is not apolypeptide consisting of the amino acid sequence given between residues49 and 466 of FIG. 4.

The ECSM4 polypeptide includes a polypeptide comprising or consisting ofthe amino acid sequence given in FIG. 4 or FIG. 5 or FIG. 7 or FIG. 12or FIG. 13 or the polypeptide encoded by the nucleotide sequence ofeither FIG. 4 between positions 1 and 1395 or FIG. 5 between positions 2and 948 or FIG. 7 or FIG. 12 or FIG. 13 is that of the ECSM4polypeptide. Preferably, the ECSM4 polypeptide of the inventioncomprises but does not consist of the amino acid sequence given in FIG.4.

Preferably, the ECSM4 polypeptide of the invention does not consist ofany of the amino acid sequences represented by SEQ ID No 18085 of EP 1074 617, SEQ ID No 211 of either WO 00/53756 or WO99/46281, SEQ ID Nos24-27, 29, 30, 33, 34, 38 or 39 of WO 01/23523, or SEQ ID No 86 of WO99/11293, or any of the amino acid sequences encoded by SEQ ID No 18084or 5096 of EP 1 074 617, SEQ ID No 210 of WO 00/53756 or WO 99/46281, orSEQ ID Nos 22,23, 96 or 98 of WO 01/23523 or SEQ ID No 31 of WO99/11293.

A twelfth aspect of the invention provides a polypeptide comprising orconsisting of the ECSM1 polypeptide or a fragment or variant or fusionthereof or a fusion of said fragment or variant.

The ECSM1 polypeptide includes a polypeptide comprising or consisting ofthe amino acid sequence given in FIG. 2. Preferably, the ECSM1polypeptide or fragment is not a polypeptide whose sequence is given inSEQ ID No 120 of WO 99/06423 or which is encoded by SEQ ID No 32 of WO99/06423 or encoded by the nucleic acid of ATCC deposit No 209145 madeon Jul. 17 1997 for the purposes of WO 99/06423.

The invention includes peptides which are derived from the ECSM4 orECSM1 polypeptides. These peptides may be considered “fragments” of theECSM4 or ECSM1 polypeptides but may be produced by de novo synthesis orby fragmentation of the polypeptide.

“Fragments” of the ECSM4 or ECSM1 polypeptide include polypeptides whichcomprise at least five consecutive amino acids of the ECSM4 or ECSM1polypeptide. Preferably, a fragment of the polypeptide comprises anamino acid sequence which is useful, for example, a fragment whichretains activity of the polypeptide, or a fragment for use in a bindingassay or is useful as a peptide for producing an antibody which isspecific for the ECSM4 or ECSM1 polypeptide. An activity of the ECSM4polypeptide may be in endothelial cell repulsive guidance. Repulsiveguidance may be tested in vivo by constructing appropriate transgenic orknock-out animal models, for example mice or zebrafish. It may also betested in vivo on cell migration assays such as Boyden chamber or videomicroscopy. Typically, the fragments have at least 8 consecutive aminoacids, preferably at least 10, more preferably at least 12 or 15 or 20or 30 or 40 or 50 consecutive amino acids of the ECSM4 or ECSM1polypeptide. Preferably, fragments of the ECSM4 polypeptide comprise butdo not consist of the amino acid sequence given in FIG. 4 or FIG. 5 orFIG. 7 or FIG. 12 or FIG. 13. Preferably, fragments of the ECSM4polypeptide comprise but do not consist of any of the amino acidsequences represented by SEQ ID No 18085 of EP 1 074 617, SEQ ID No 211of either WO 00/53756 or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34,38 or 39 of WO 01/23523, or SEQ ID No 86 of WO 99/11293, or any of theamino acid sequences encoded by SEQ ID No 18084 or 5096 of EP 1 074 617,SEQ ID No 210 of WO 00 53756 or WO 99/46281, or SEQ ID Nos 22, 23, 96 or98 of WO 01/23523 or SEQ ID No 31 of WO 99/11293.

Typically, the fragments of ECSM4 polypeptide are ones which haveportions of the amino acid sequence shown in FIG. 4 or FIG. 12.

Typically, the fragments of ECSM1 polypeptide are ones which haveportions of the amino acid sequence shown in FIG. 2.

In a preferred embodiment of the thirteenth aspect of the invention, afragment of the ECSM4 polypeptide is a fragment which has the sequenceLSQSPGAVPQALVAWRA (SEQ ID NO:6), DSVLTPEEVALCLEL (SEQ ID NO:7),TYGYISVPTA (SEQ ID NO:8), KGGVLLCPPRPCLTPT (SEQ ID NO:9), WLADTW (SEQ IDNO:10), WLADTWRSTSGSRD (SEQ ID NO:11), SPPTTYGYIS (SEQ ID NO:12),GSLANGWGSASEDNAASARASLVSSSDGSFLAD (SEQ ID NO:13) or FARALAVAVD (SEQ IDNO:14) or has a sequence of at least 5 or 8 or 10 residues of any ofthese sequences. These peptides correspond to amino acids 165-181,274-288, 311-320, 336-351, 8-13, 8-21, 307-316, 355-387 and 390-399respectively of the human ECSM4 polypeptide shown in FIG. 4. PeptidesWLADTW (SEQ ID NO:10), WLADTWRSTSGSRD (SEQ ID NO:11), SPPTTYGYIS (SEQ IDNO:12), GSLANGWGSASEDNAASARASLVSSSDGSFLAD (SEQ ID NO:13) and FARALAVAVD(SEQ ID NO:14) represent conserved regions between the mouse and humanhomologues of the ECSM4 polypeptide, and between the ECSM4 polypeptideand the mouse dutt1 protein. The peptides LSQSPGAVPQALVAVRA (SEQ IDNO:6), DSVLTPEEVALCLEL (SEQ ID NO:7), TYGYISVPTA (SEQ ID NO:8) andKGGVLLCPPRPCLTPT (SEQ ID NO:9) may be useful in raising antibodies.

Preferred peptides are peptides of at least 5 or 8 or 10 or 12 or 15 or20 consecutive amino acid residues from these conserved sequences.Peptides of ECSM4 which affect cell migration and/or growth and/orvascular development are particularly preferred. They can be identifiedin suitable screening systems.

In a further preferred embodiment of this aspect of the invention, afragment of the ECSM4 polypeptide is a fragment which has the sequenceGGDSLLGGRGSL, LLQPPARGHAHDGQALSTDL, EPQDYTEPVE, TAPGGQGAPWAEE orERATQEPSEHGP or has a sequence of at least 5 or 8 or 10 residues of anyof these sequences. These peptides correspond to regions of the humanECSM4 polypeptide (located at residues 4-16, 91-109, 227-236,288-300 and444-455 respectively in the sequence given in FIG. 12) which are not, orare poorly, conserved in the mouse homologue (see FIG. 14). As describedbelow, such peptides may be particularly useful in raising antibodies tothe human ECSM4 polypeptide.

According to the transmembrane domain predicting software program calledPRED-TMR (available at the Biophys.Biol. internet site) and an aminoacid sequence alignment with the human protein Robo1 (whosetransmembrane region is known), residues 1-467 as shown in FIG. 12 arelikely to be extracellular, and in addition to being extracellularlyexposed, may include the binding site of the natural ligand. Hencefragments of ECSM4 which include or consist of a sequence within theextracellular domain of residues 1-467 of FIG. 12 may represent usefulfragments for raising antibodies selective for cells expressing ECSM4 ontheir surface and which may also be useful in modulating the activity ofthe polypeptide ECSM4.

Hence, preferred fragments of the ECSM4 polypeptide are those fragmentsof the polypeptide sequence of FIG. 12 which comprise at least 1, 3 or5, amino acid residues which are not conserved when compared to themouse ECSM4 (as shown in FIG. 13). More preferably at least 7, 9, 11 or13 amino acid residues in the fragment are not conserved between humanECSM4 and mouse ECSM4, and still more preferably at least 15, 17, 19 or21 residues of the fragment are not conserved between human ECSM4 andmouse ECSM4. The sequence of such fragments may be determined from thealignment of the human and mouse amino acid sequences shown in FIG. 14.

It will be appreciated that fragments of the ECSM4 or ECSM1 polypeptideof the invention are particularly useful when fused to otherpolypeptides, such as glutathione-S-transferase (GST), green fluorescentprotein (GFP), vesicular stomatitis virus glycoprotein (VSVG) or keyholelimpet haemacyanin (KLH). Fusions of the polypeptide, or fusions offragments or variants of the polypeptide of the invention are includedin the scope of the invention.

Other useful fragments of ECSM4 are those which are able to bind aligand selective for ECSM4. Suitable methods for identification ofligands such as peptides or other molecules which bind ECSM4 isdiscussed in more detail above. Such peptides or other ECSM4-bindingmolecules can be used to identify the amino acid sequences present inECSM4 which are responsible for ligand binding. Identification of thosefragments of ECSM4 which, when isolated from the rest of the molecule,are still able to bind a ligand of ECSM4 can be achieved by means of ascreen. Typically, such a screen will comprise contacting a ligand ofECSM4 with a test fragment of the ECSM4 polypeptide and determining ifthe test fragment binds the ligand. Fragments of ECSM4 are within thescope of the invention, and may be particularly useful in medicine. Afragment of ECSM4 which binds the natural ECSM4 ligand may neutralisethe effect of the ligand and thereby affect endothelial cell migration,growth and/or vascular development. Hence, administration of fragmentsof ECSM4 may be useful in the treatment of diseases or conditions whereendothelial cell migration, growth and/or vascular development need tobe modulated. Examples of such diseases include cancer andartherosclerosis.

A “fusion” of the ECSM4 or ECSM1 polypeptide or a fragment or variantthereof provides a molecule comprising a polypeptide of the inventionand a further portion. It is preferred that the said further portionconfers a desirable feature on the said molecule; for example, theportion may useful in detecting or isolating the molecule, or promotingcellular uptake of the molecule. The portion may be, for example, abiotin moiety, a radioactive moiety, a fluorescent moiety, for example asmall fluorophore or a green fluorescent protein (GFP) fluorophore, aswell known to those skilled in the art. The moiety may be an immunogenictag, for example a Myc tag, as known to those skilled in the art or maybe a lipophilic molecule or polypeptide domain that is capable ofpromoting cellular uptake of the molecule or the interactingpolypeptide, as known to those skilled in the art.

A “variant” of the ECSM4 or ECSM1 polypeptide includes natural variants,including allelic variants and naturally-occurring mutant forms andvariants with insertions, deletions and substitutions, eitherconservative or non-conservative, where such changes do notsubstantially alter the activity of the said polypeptide. In the case ofthe ECSM4 polypeptide, as an endothelial specific homologue of the humanroundabout 1 it may well be involved in endothelial cell repulsiveguidance. In addition, polypeptides which are elongated as a result ofan insertion or which are truncated due to deletion of a region areincluded in the scope of the invention. For example, deletion ofcytoplasmically-located regions may be useful in creation of “dominantnegative” or “dominant positive” forms of the polypeptide. Similarly,deletion of a transmembrane region of the polypeptide may produce suchforms.

By “conservative substitution” is intended combinations such as Gly,Ala; Val, Ile, Leu; Asp, Glu; Asn, Gln; Ser, Thr; Lys, Arg; and Phe,Tyr.

By “non-conservative substitution” we include other substitutions, suchas those where the substituted residue mimics a particular modificationof the replaced residue, for example a phosphorylated tyrosine or serinemay be replaced by aspartate or glutamate due to the similarity of theaspartate or glutamate side chain to a phosphorylated residue (ie theycarry a negative charge at neutral pH).

Further non-conservative substitutions which are included in the term“variants” are point mutations which alter one, sometimes two, andusually no more than three amino acids. Such mutations are well known inthe art of biochemistry and are usually designed to insert or remove adefined characteristic of the polypeptide. Another type ofnon-conservative mutation is the alteration or addition of a residue toa cysteine or lysine residue which can then be used with maleimide orsuccinimide cross-linking reagents to covalently conjugate thepolypeptide to another moiety. Non-glycosylated proteins may be mutatedto convert an asparagine to the recognition motif N-X-S/T for N-linkedglycosylation. Such a modification may be useful to create a tag forpurification of the polypeptide using Concanavalin A-linked beads.

Such variants may be made using the methods of protein engineering andsite-directed mutagenesis well known in the art.

Variants of the ECSM4 polypeptide include polypeptides comprising asequence with at least 65% identity to the amino acid sequence given inFIG. 4 or FIG. 7 or FIG. 12 or FIG. 13, preferably at least 70% or 80%or 85% or 90% identity to said sequence, and more preferably at least95% or 98% identity to said amino acid sequence.

Variants of the ECSM1 polypeptide include polypeptides comprising asequence with at least 65% identity to the amino acid sequence given inFIG. 2, preferably at least 70% or 80% or 85% or 90% identity to saidsequence, and more preferably at least 95% or 98% identity to said aminoacid sequence.

Percent identity can be determined by, for example, the LALIGN program(Huang and Miller, Adv. Appl. Math. (1991) 12:337-357) at the Expasyfacility internet site using as parameters the global alignment option,scoring matrix BLOSUM62, opening gap penalty −14, extending gap penalty−4.

A thirteenth aspect of the invention provides a polynucleotide encodingthe ECSM4 polypeptide of the invention, or the complement thereof or apolynucleotide which selectively hybridises to either of these whichpolynucleotide is not any one of the clones corresponding to GenBankAccession No AK000805 or the ESTs whose GenBank Accession Nos are givenin Table 11 or Table 12.

GenBank Accession No AK000805 corresponds to a cDNA sequence cloned inthe vector pME18SFL3. ESTs listed in Table 11 represent nucleotidesequences which can be assembled into the contig sequence shown in FIG.5. ESTs listed in Table 12 represent nucleotide sequences which can beassembled into the mouse nucleotide cluster sequence (Mm.27782) given inFIG. 7.

Preferably, the polynucleotide of this aspect of the invention does notconsist of any one of the nucleotide sequences represented by SEQ ID No18084 or 5096 of EP 1 074 617, SEQ ID No 210 of WO 00 53756 or WO99/46281, or SEQ ID Nos 22, 23, 96 or 98 of WO 01/23523 or SEQ ID No 31of WO 99/11293, or their complement.

Also preferably, the polynucleotide of this aspect of the invention isnot a polynucleotide which encodes a polypeptide consisting of the aminoacid sequence represented by any one of SEQ ID No 18085 of EP 1 074 617,SEQ ID No 211 of either WO 00/53756 or WO99/46281, SEQ ID Nos 24-27, 29,30, 33, 34, 38 or 39 of WO 01/23523, or SEQ ID No 86 of WO 99/11293

Polynucleotides of the thirteenth aspect of the invention are describedin more detail below.

A fourteenth aspect of the invention provides a polynucleotide encodingthe ECSM1 polypeptide or the complement thereof or a polynucleotidewhich selectively hybridises to either of these, according to thetwelfth aspect of the invention provided that the polynucleotide is notone present in ATCC deposit No 209145 or the clone corresponding toGenBank Accession No AC011526 or the ESTs whose GenBank Accession Nosare given in Table 10.

By “encoding a polypeptide according to the twelfth aspect of theinvention” we mean that the polynucleotide is one which encodes an ECSM1polypeptide of the invention and is not one which encodes a polypeptidewhose sequence is given in SEQ ID No 120 of WO 99/06423 or which isencoded by SEQ ID No 32 or by the nucleic acid included in themicrobiological deposit corresponding to American Type CultureCollection (ATCC) No. 209145 made on Jul. 17, 1997.

ATCC deposit No 209145 comprises a pSport1 vector which includes a 765base nucleotide sequence.

The polynucleotide sequence given in SEQ ID No 32 of WO 99/06423 issimilar to the nucleotide sequence shown in FIG. 2. The sequence of SEQID No 32 given in WO 99/06423 may be capable of encoding part of theECSM1 polypeptide of the invention. Due to degeneracy of the geneticcode however, a polynucleotide sequence may encode the ECSM1 polypeptideof the invention without having a nucleotide sequence as given in WO99/06423. In a similar manner, a polynucleotide sequence may encode the(full length) ECSM4 polypeptide of the invention without having the samesequence as that given in FIG. 4 or FIG. 5 or FIG. 12. Suchpolynucleotides are within the scope of this invention.

Hence, it will be appreciated that a polynucleotide of the thirteenthaspect of the invention is preferably not one whose nucleotide sequenceis given in FIG. 4, and that a polynucleotide of the fourteenth aspectof the invention is preferably not a polynucleotide which is disclosedin WO 99/06423, such as SEQ ID No 32 disclosed therein or its complementor variants or the corresponding cDNA sequence deposited under AccessionNo 209145 at the ATCC or a polynucleotide fragment capable of encoding apolypeptide whose amino acid sequence comprises the sequence given inSEQ ID No 120 of WO 99/06423.

A polynucleotide of the thirteenth or fourteenth aspects of theinvention may encode a variant of the ECSM4 or ECSM1 polypeptide asdescribed above. In addition, the insertions and/or deletions within theECSM4 or ECSM1 polypeptide may lead to frameshift mutations which mayencode truncated (or elongated) polypeptide products, and insertions,deletions or other mutations may lead to the introduction of stop codonswhich encode truncate polypeptide products.

The polynucleotide of the invention may be DNA or RNA. It is preferredif it is DNA.

The polynucleotide may or may not contain introns. It is preferred if itdoes not contain introns.

The polynucleotide may be single stranded or double stranded or amixture of either.

The polynucleotide of the invention has at least 10 nucleotides, andpreferably at least 15 nucleotides and more preferably at least 30nucleotides. In a further preference, the polynucleotide is more than 50nucleotides, more preferably at least 100 nucleotides, and still morepreferably the polynucleotide is at least 500 nucleotides. Thepolynucleotide may be more than 1 kb, and may comprise more than 5 kb.

The invention also includes a polynucleotide which is able toselectively hybridise to a polynucleotide which encodes the ECSM4 orECSM1 polypeptide or a fragment or variant or fusion thereof, or afusion of said variant or fragment. Preferably, said polynucleotide isat least 10 nucleotides, more preferably at least 15 nucleotides andstill more preferably at least 30 nucleotides in length. The saidpolynucleotide may be longer than 100 nucleotides and may be longer than200 nucleotides, but preferably the said polynucleotide is not longerthan 250 nucleotides. Such polynucleotides are useful in procedures as adetection tool to demonstrate the presence of the polynucleotide in asample. Such a sample may be a sample of DNA, such as a bacterialcolony, fixed on a membrane or filter.

Preferably, the polynucleotide which is capable of selectivelyhybridising as said is not any one of the nucleotide sequencesrepresented by SEQ ID No 18084 or 5096 of EP 1 074 617, SEQ ID No 210 ofWO 00 53756 or WO 99/46281, or SEQ ID Nos 22, 23, 96 or 98 of WO01/23523 or SEQ ID No 31 of WO 99/11293.

By “selectively hybridise” we mean that the polynucleotide hybridisesunder conditions of high stringency. DNA-DNA, DNA-RNA and RNA-RNAhybridisation may be performed in aqueous solution containing between0.1×SSC and 6×SSC and at temperatures of between 55° C. and 70° C. It iswell known in the art that the higher the temperature or the lower theSSC concentration the more stringent the hybridisation conditions. By“high stringency” we mean 2×SSC and 65° C. 1×SSC is 0.15M NaCl/0.015Msodium citrate. Polynucleotides which hybridise at high stringency areincluded within the scope of the claimed invention.

In another embodiment, the polynucleotide can be used as a primer in thepolymerase chain reaction (PCR), and in this capacity a polynucleotideof between 15 and 30 nucleotides is preferred. A polynucleotide ofbetween 20 and 100 nucleotides is preferred when the fragment is to beused as a mutagenic PCR primer. It is particularly preferred if the PCRprimer (when not being used to mutate a nucleic acid) contains about 15to 30 contiguous nucleotides (ie perfect matches) from the nucleotidesequence given in FIG. 4 or FIG. 7 or FIG. 12 or FIG. 13 from thenucleotide sequence given in FIG. 2. Clearly, if the PCR primers areused for mutagenesis, differences compared to the sequence will bepresent.

Primers which are suitable for use in a polymerase chain reaction (PCR;Saiki et al (1988) Science 239, 487-491) are preferred. Suitable PCRprimers may have the following properties:

It is well known that the sequence at the 5′ end of the oligonucleotideneed not match the target sequence to be amplified.

It is usual that the PCR primers do not contain any complementarystructures with each other longer than 2 bases, especially at their 3′ends, as this feature may promote the formation of an artifactualproduct called “primer dimer”. When the 3′ ends of the two primershybridize, they form a “primed template” complex, and primer extensionresults in a short duplex product called “primer dimer”.

Internal secondary structure should be avoided in primers. For symmetricPCR, a 40-60% G+C content is often recommended for both primers, with nolong stretches of any one base. The classical melting temperaturecalculations used in conjunction with DNA probe hybridization studiesoften predict that a given primer should anneal at a specifictemperature or that the 72° C. extension temperature will dissociate theprimer/template hybrid prematurely. In practice, the hybrids are moreeffective in the PCR process than generally predicted by simple T_(m)calculations.

Optimum annealing temperatures may be determined empirically and may behigher than predicted. Taq DNA polymerase does have activity in the37-55° C. region, so primer extension will occur during the annealingstep and the hybrid will be stabilised. The concentrations of theprimers are equal in conventional (symmetric) PCR and, typically, within0.1- to 1 nM range.

When a pair of suitable nucleic acids of the invention are used in a PCRit is 5 convenient to detect the product by gel electrophoresis andethidium bromide staining. As an alternative to detecting the product ofDNA amplification using agarose gel electrophoresis and ethidium bromidestaining of the DNA, it is convenient to use a labelled oligonucleotidecapable of hybridising to the amplified DNA as a probe. When theamplification is by a PCR the oligonucleotide probe hybridises to theinterprimer sequence as defined by the two primers. The probe may belabelled with a radionuclide such as ³²P, ³³P and ³⁵S using standardtechniques, or may be labelled with a fluorescent dye. When theoligonucleotide probe is fluorescently labelled, the amplified DNAproduct may be detected in solution (see for example Balaguer et al(1991) “Quantification of DNA sequences obtained by polymerase chainreaction using a bioluminescence adsorbent” Anal. Biochem. 195, 105-110and Dilesare et al (1993) “A high-sensitivityelectrochemiluminescence-based detection system for automated PCRproduct quantitation” BioTechniques 15, 152-157.

PCR products can also be detected using a probe which may have afluorophore-quencher pair or may be attached to a solid support or mayhave a biotin tag or they may be detected using a combination of acapture probe and a detector probe.

Fluorophore-quencher pairs are particularly suited to quantitativemeasurements of PCR reactions (eg RT-PCR). Fluorescence polarisationusing a suitable probe may also be used to detect PCR products.

Oligonucleotide primers can be synthesised using methods well known inthe art, for example using solid-phase phosphoramidite chemistry.

A polynucleotide or oligonucleotide primer of the invention may containone or more modified bases or may contain a backbone which has beenmodified for stability purposes or for other reasons. By modified weincluded for example, tritylated bases and unusual bases such asinosine. A variety of modifications can be made to DNA and RNA and theseare included in the scope of the invention.

In a preferred embodiment, the polynucleotides of the invention aredetectably labelled. Suitable detectable labels are described in detailabove.

A fifteenth aspect of the invention provides an expression vectorcomprising a polynucleotide as described above. Typically, thepolynucleotides are those which encode the polypeptides ECSM1 or ECSM4or a fragment, variant or fusion thereof.

By “expression vector” we mean one which is capable, in an appropriatehost, of expressing a polypeptide encoded by the polynucleotide.

Such vectors may be useful in expressing the encoded polypeptide in ahost cell for production of useful quantities of the polypeptide, or maybe useful in medicine. Expression vectors comprising a polynucleotideaccording to the thirteenth or fourteenth aspects of the invention whichare suitable for use in gene therapy are within the scope of theinvention. Administration of a gene therapy vector capable of expressingthe ECSM4 polypeptide may be useful in modulating or inhibitingangiogenesis, since this polypeptide is likely to be a repulsiveguidance receptor. Similarly, gene therapy vectors capable of expressingfragments or mutants of ECSM4 on the cell surface, which fragments ormutants are capable of binding the ECSM4 cognate ligand but are not ableto convey the normal downstream signal (for example, because thenecessary cytosolic portion of the polypeptide is deleted or mutated soas to not be functional or capable of binding normally interactingcellular proteins) may also be useful in modulating angiogenesis in anindividual.

Hence, in a preferred embodiment, the vector is one which is suitablefor use in gene therapy. Examples of suitable vectors and methods oftheir introduction into cells are given in more detail below. Inparticular, the gene therapy methods and vectors described in relationto the use of promoters of ECSM4 may also be used in relation to the useof ECSM4 coding sequences or antisense in gene therapy.

It will be appreciated that the polynucleotide comprised within theexpression vector of this aspect of the invention may be one whichencodes the polypeptide ECSM4 or ECSM1 or a fragment or variant thereof,or the polynucleotide may be one which is capable of selectivelyhybridising to the ECSM4 or ECSM1 coding region. Polynucleotides whichare capable of hybridising to the ECSM4 or ECSM1 coding region areuseful as antisense polynucleotides which may decrease the expressionlevel of ECSM4 or ECSM1 within a target cell. The design of suitable andeffective antisense polynucleotides based on a known coding sequence isknown in the art of gene therapy.

Preferably, the expression vector of this aspect of the invention is onewhich does not contain a polynucleotide sequence represented by any oneof SEQ ID No 18085 of EP 1 074 617, SEQ ID No 211 of either WO 00/53756or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO01/23523, or SEQ ID No 86 of WO 99/11293 or their complement. Alsopreferably, the said vector is one which does not contain apolynucleotide encoding a polypeptide whose amino acid sequence isrepresented by any one of SEQ ID No 18085 of EP 1 074 617, SEQ ID No 211of either WO 00/53756 or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34,38 or 39 of WO 01/23523, or SEQ ID No 86 of WO 99/11293.

Both the amount of therapeutic protein or therapeutic polynucleotideproduced and the duration of production are important issues in genetherapy. Consequently, the use of viral vectors capable of cellular geneintegration (eg retroviral vectors) may be more beneficial thannon-integrating alternatives (eg adenovirus derived vectors) whenrepeated therapy is undesirable for immunogenicity reasons.

By “therapeutic polynucleotide” or “therapeutic protein” we includeECSM4 and ECSM1 coding sequences, the polypeptide product encoded bysaid coding sequences, and ECSM4 antisense polynucleotides. Thetherapeutic effect of said polynucleotides or proteins may includepro-angiogenic or anti-angiogenic effects, depending on the precisetherapeutic agent administered. For example, an expression vectorsuitable for gene therapy which comprises a polynucleotide which isantisense to at least part of the ECSM4 coding region may haveanti-angiogenic activity when expressed in a host cell or patient if itsuppresses expression of a molecule which is required for angiogenesis.If the polynucleotide comprised within the expression vector encodes apolypeptide which is required for inhibition of angiogenesis (forexample, because said polypeptide has endotihelial cell repulsiveguidance activity), then expression of the antisense may also beanti-angiogenic.

Conversely, if said the expression vector comprises a polynucleotide ofthe invention which polynucleotide suppresses expression of a moleculewhose activity is required to decrease vascular growth (for example,because said molecule is an endothelial cell repulsive guidancemolecule) or encodes a polypeptide whose activity is required forangiogenesis, administration of the said vector may be pro-angiogenic.

Where the therapeutic gene is maintained extrachromosomally, the highestlevel of expression is likely to be achieved using viral promoters, forexample, the Rous sarcoma virus long terminal repeat (Ragot et al (1993)Nature 361, 647-650; Hyde et al (1993) Nature 362, 250-255) and theadenovirus major late promoter. The latter has been used successfully todrive the expression of a cystic fibrosis transmembrane conductanceregulator (CFTR) gene in lung epithelium (Rosenfeld et al (1992) Cell68, 143-155). Since these promoters function in a broad range of tissuesthey may not be suitable to direct cell-type-specific expression unlessthe delivery method can be adapted to provide the specificity. However,somatic enhancer sequences could be used to give cell-type-specificexpression in an extrachromosomal setting.

As described in more detail below, the ECSM4 regulatory/promoter regionis an example of a regulatory region capable of conferring endothelialcell selective expression, preferably selective to endothelial cells ofneovasculature (ie, angiogenic endothelial cells) on an operativelylinked coding region. As outlined above, such a coding region may encodean antisense polynucleotide.

Where withdrawal of the gene-vector construct is not possible, it may benecessary to add a suicide gene to the system to abort toxic reactionsrapidly. The herpes simplex virus thymidine kinase gene, when transducedinto cells, renders them sensitive to the drug ganciclovir, creating theoption of killing the cells quickly.

The use of ectotropic viruses, which are species specific, may provide asafer alternative to the use of amphotropic viruses as vectors in genetherapy. In this approach, a human homologue of the non-human,ectotropic viral receptor is modified in such a way so as to allowrecognition by the virus. The modified receptor is then delivered tocells by constructing a molecule, the front end of which is specifiedfor the targeted cells and the tail part being the altered receptor.Following delivery of the receptor to its target, the geneticallyengineered ectotropic virus, carrying the therapeutic gene, can beinjected and will only integrate into the targeted cells.

Virus-derived gene transfer vectors can be adapted to recognise onlyspecific cells so it may be possible to target to an endothelial cell,such as endothelial cells within a tumour. Similarly, it is possible totarget expression of an therapeutic gene to the endothelial cell, usingan endothelial cell-specific promoter such as that for the ECSM4 orECSM1 genes.

One of the ECSM genes or a part of the genes or a polynucleotidecomprising an antisense to the gene may be introduced into the cell in avector such that the gene remains extrachromosomal. In such a situation,the gene will be expressed by the cell from the extrachromosomallocation. Vectors for introduction of genes both for recombination andfor extrachromosomal maintenance are known in the art, and any suitablevector may be used. Methods for introducing DNA into cells such aselectroporation, calcium phosphate co-precipitation and viraltransduction are known in the art, and the choice of method is withinthe competence of the ordinary skilled person. Cells transformed withthe wild-type novel gene can be used as model systems to study cancerremission and drug treatments which promote such remission.

A variety of methods have been developed to operably linkpolynucleotides, especially DNA, to vectors, for example, viacomplementary cohesive termini. For instance, complementary homopolymertracts can be added to the DNA segment to be inserted into the vectorDNA. The vector and DNA segment are then joined by hydrogen bondingbetween the complementary homopolymeric tails to form recombinant DNAmolecules.

Synthetic linkers containing one or more restriction sites provide analternative method of joining the DNA segment to vectors. The DNAsegment, generated by endonuclease restriction digestion as describedearlier, is treated with bacteriophage T4 DNA polymerase or E.coli DNApolymerase I, enzymes that remove protruding, 3′-single-stranded terminiwith their 3′-5′-exonucleolytic activities, and fill in recessed 3′-endswith their polymerising activities.

The combination of these activities therefore generates blunt-ended DNAsegments. The blunt-ended segments are then incubated with a largermolar excess of linker molecules in the presence of an enzyme that isable to catalyse the ligation of blunt-ended DNA molecules, such asbacteriophage T4 DNA ligase. Thus, the products of the reaction are DNAsegments carrying-polymeric linker sequences at their ends. These DNAsegments are then cleaved with the appropriate restriction enzyme andligated to an expression vector that has been cleaved with an enzymethat produces termini compatible with those of the DNA segment.

Synthetic linkers containing a variety of restriction endonuclease siteare commercially available from a number of sources includingInternational Biotechnologies Inc., New Haven, Conn., USA.

A desirable way to modify the DNA encoding the polypeptide of theinvention is to use PCR. This method may be used for introducing the DNAinto a suitable vector, for example by engineering in suitablerestriction sites, or it may be used to modify the DNA in other usefulwasy as is known in the art.

In this method the DNA to be enzymatically amplified is flanked by twospecific primers which themselves become incorporated into the amplifiedDNA. The said specific primers may contain restriction endonucleaserecognition sites which can be used for cloning into expression vectorsusing methods known in the art.

The DNA (or in the case of retroviral vectors, RNA) is then expressed ina suitable host to produce a polypeptide comprising the polypeptide ofthe invention. Thus, the DNA encoding the polypeptide constituting thepolypeptide of the invention may be used in accordance with knowntechniques, appropriately modified in view of the teachings containedherein, to construct an expression vector, which is then used totransform an appropriate host cell for the expression and production ofthe polypeptide of the invention. Such techniques include thosedisclosed in U.S. Pat. Nos. 4,440,859 issued 3 Apr. 3, 1984 to Rutter etal, 4,530,901 issued Jul. 23, 1985 to Weissman, 4,582,800 issued Apr.15, 1986 to Crowl, 4,677,063 issued Jun. 30, 1987 to Mark et al,4,678,751 issued Jul. 7, 1987 to Goeddel, 4,704,362 issued Nov. 3, 1987to Itakura et al, 4,710,463 issued Dec. 1, 1987 to Murray, 4,757,006issued Jul. 12, 1988 to Toole, Jr. et al, 4,766,075 issued Aug. 23, 1988to Goeddel et al and 4,810,648 issued Mar. 7, 1989 to Stalker, all ofwhich are incorporated herein by reference.

The DNA (or in the case or retroviral vectors, RNA) encoding thepolypeptide constituting the polypeptide of the invention may be joinedto a wide variety of other DNA sequences for introduction into anappropriate host. The companion DNA will depend upon the nature of thehost, the manner of the introduction of the DNA into the host, andwhether episomal maintenance or integration is desired.

Generally, the DNA is inserted into an expression vector, such as aplasmid, in proper orientation and correct reading frame for expression.If necessary, the DNA may be linked to the appropriate transcriptionaland translational regulatory control nucleotide sequences recognised bythe desired host, although such controls are generally available in theexpression vector. The vector is then introduced into the host throughstandard techniques. Generally, not all of the hosts will be transformedby the vector. Therefore, it will be necessary to select for transformedhost cells. One selection technique involves incorporating into theexpression vector a DNA sequence, with any necessary control elements,that codes for a selectable trait in the transformed cell, such asantibiotic resistance. Alternatively, the gene for such selectable traitcan be on another vector, which is used to co-transform the desired hostcell.

Host cells that have been transformed by the expression vector of theinvention are then cultured for a sufficient time and under appropriateconditions known to those skilled in the art in view of the teachingsdisclosed herein to permit the expression of the polypeptide, which canthen be recovered.

Many expression systems are known, including bacteria (for example,E.coli and Bacillus subtilis), yeasts (for example Sacchlaromycescerevisiae), filamentous fungi (for example Aspergillus), plant cells,animal cells and insect cells.

The vectors typically include a prokaryotic replicon, such as the ColE1ori, for propagation in a prokaryote, even if the vector is to be usedfor expression in other, non-prokaryotic, cell types. The vectors canalso include an appropriate promoter such as a prokaryotic promotercapable of directing the expression (transcription and translation) ofthe genes in a bacterial host cell, such as E.coli, transformedtherewith.

A promoter is an expression control element formed by a DNA sequencethat permits binding of RNA polymerase and transcription to occur.Promoter sequences compatible with exemplary bacterial hosts aretypically provided in plasmid vectors containing convenient restrictionsites for insertion of a DNA segment of the present invention.

Typical prokaryotic vector plasmids are pUC18, pUC19, pBR322 and pBR329available from Biorad Laboratories, (Richmond, Calif., USA) and pTrc99Aand pKK223-3 available from Pharmacia, Piscataway, N.J., USA.

A typical mammalian cell vector plasmid is pSVL available fromPharmacia, Piscataway, N.J., USA. This vector uses the SV40 latepromoter to drive expression of cloned genes, the highest level ofexpression being found in T antigen-producing cells, such as COS-1cells.

An example of an inducible mammalian expression vector is pMSG, alsoavailable from Pharmacia. This vector uses the glucocorticoid-indulciblepromoter of the mouse mammary tumour virus long terminal repeat to driveexpression of the cloned gene.

Useful yeast plasmid vectors are pRS403-406 and pRS413-416 and aregenerally available from Stratagene Cloning Systems, La Jolla, Calif.92037, USA. Plasmids pRS403, pRS404, pRS405 and pRS406 are YeastIntegrating plasmids (YIps) and incorporate the yeast selectable markersHIS3, TRP1, LEU2 and URA3. Plasmids pRS413-416 are Yeast Centromereplasmids (Ycps).

Other vectors and expression systems are well known in the art for usewith a variety of host cells.

A sixteenth aspect of the invention provides a recombinant host cellcomprising a polynucleotide or vector of the invention.

The polynucleotide of the invention includes polynucleotides encoding acompound of the third aspect of the invention (where both the moietywhich selectively binds and the further moiety are polypeptides whichare fused) or an ECSM4 or ECSM1 polypeptide of the invention or afragment or fusion or variant thereof as defined above.

The host cell can be either prokaryotic or eukaryotic. Bacterial cellsare preferred prokaryotic host cells and typically are a strain ofE.coli such as, for example, the E.coli strains DH5 available fromBethesda Research Laboratories Inc., Bethesda, Md., USA, and RR1available from the American Type Culture Collection (ATCC) of Rockville,Md., USA (No. ATCC 31343). Preferred eukaryotic host cells includeyeast, insect and mammalian cells, preferably vertebrate cells such asthose from a mouse, rat, monkey or human fibroblastic and kidney celllines. Yeast host cells include YPH499, YPH500 and YPH501 which aregenerally available from Stratagene Cloning Systems, La Jolla, Calif.92037, USA. Preferred mammalian host cells include Chinese hamster ovary(CHO) cells available from the ATCC as CRL 1658 and 293 cells which arehuman embryonic kidney cells. Preferred insect cells are Sf9 cells whichcan be transfected with baculovirus expression vectors.

Transformation of appropriate cell hosts with a DNA construct of thepresent invention is accomplished by well known methods that typicallydepend on the type of vector used. With regard to transformation ofprokaryotic host cells, see, for example, Cohen et al (1972) Proc. Natl.Acad. Sci. USA 69, 2110 and Sambrook et al (1989) Molecular Cloning, ALaboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor,N.Y. Transformation of yeast cells is described in Sherman et al (1986)Methods In Yeast Genetics, A Laboratory Manual, Cold Spring Harbor, N.Y.The method of Beggs (1978) Nature 275, 104-109 is also useful. Withregard to vertebrate cells, reagents useful in transfecting such cells,for example calcium phosphate and DEAE-dextran or liposome formulations,are available from Stratagene Cloning Systems, or Life TechnologiesInc., Gaithersburg, Md. 20877, USA.

Electroporation is also useful for transforming and/or transfectingcells and is well known in the art for transforming yeast cells,bacterial cells, insect cells and vertebrate cells.

For example, many bacterial species may be transformed by the methodsdescribed in Luchansky et al (1988) Mol. Microbiol. 2, 637-646incorporated herein by reference. The greatest number of transformantsis consistently recovered following electroporation of the DNA-cellmixture suspended in 2.5 PEB using 6250V per cm at 25 μFD.

Methods for transformation of yeast by electroporation are disclosed inBecker & Guarente (1990) Methods Enzymol. 194, 182.

Successfully transformed cells, ie cells that contain a DNA construct ofthe present invention, can be identified by well-known techniques. Forexample, cells resulting from the introduction of an expressionconstruct of the present invention can be grown to produce thepolypeptide of the invention. Cells can be harvested and lysed and theirDNA content examined for the presence of the DNA using a method such asthat described by Southern (1975) J. Mol. Biol. 98, 503 or Berent et al(1985) Biotech. 3, 208. Alternatively, the presence of the protein inthe supernatant can be detected using antibodies as described below.

In addition to directly assaying for the presence of recombinant DNA,successful transformation can be confirmed by well known immunologicalmethods when the recombinant DNA is capable of directing the expressionof the protein. For example, cells successfully transformed with anexpression vector produce proteins displaying appropriate antigenicity.

Samples of cells suspected of being transformed are harvested andassayed for the protein using suitable antibodies.

The host cell may be a host cell within an animal body. Thus, transgenicanimals which express a polypeptide of the first or third aspects of theinvention by virtue of the presence of the transgene are included.Preferably, the transgenic animal is a rodent such as a mouse.Transgenic animals can be made using methods well known in the art.

Polynucleotides encoding the polypeptide ECSM4 may be useful ingenerating transgenic non-human mammals wherein the ECSM4 is mutated insome way. For example, the mouse ECSM4 genomic coding region may bemutated in a mouse so as to produce an ECSM4 polypeptide which isincapable of binding its natural ligand, or incapable of correctlyinteracting with intracellular components. Such a mutated ECSM4polypeptide may produce a disease in the mouse which is very similar toa disease involving abnormal vascularisation in humans.

Hence, non-human mammals, especially rodents such as mice and rats, areuseful as models of diseases involving abnormal vascularisation.

Alternatively, mammals lacking the ECSM4 gene (“knock-outs”) or lackingan ECSM4 genomic coding region which is capable of being transcribed orof expressing the ECSM4 polypeptide, may be useful in providing a meansof generating antibodies selective for the human ECSM4 polypeptide. Suchmammals, especially mice, are likely to be particularly useful since thehigh level of homology between the human and mouse ECSM4 polypeptidesmay prevent human ECSM4 polypeptide from being antigenic in mice who doexpress the ECSM4 polypeptide.

A potentially more accurate animal model of diseases involving abnormalvascularisation may be made by addition to the genome of a transgenicanimal as described above, or replacing the genomic ECSM4 of an animalwith, the gene for human ECSM4 which has been mutated. Suitably, thehuman ECSM4 inserted will be under control of an endothelial selectivepromoter and regulatory region. Preferably, the promoter and regulatoryregions are those of the host animal ECSM4 gene. An animal who genome ismodified in this way will express the dysfunctional human ECSM4, andtherefore will be useful in testing the efficacy of drugs and antibodiesin the diagnosis, prognosis and treatment of diseases involving abnormalvascularisation in humans.

Such knockout or transgenic mammals are within the scope of theinvention and antibodies generated using such mammals and compoundscomprising them are also included within the scope of the invention.

A seventeenth aspect of the invention provides a method of producing apolypeptide of the invention, the method comprising expressing apolynucleotide as described above or culturing a host cell as describedherein.

It will be appreciated that in order to produce the ECSM1 polypeptide,the host cell may comprise a polynucleotide encoding a polypeptide whoseamino acid sequence includes the sequence given in FIG. 2, and that inorder to produce the ECSM4 polypeptide the host cell may comprise apolynucleotide encoding the polypeptide whose amino acid sequence isgiven in FIG. 4 or FIG. 7 or FIG. 12 and so on.

Preferably, the polynucleotide expressed does not consist of any one ofthe nucleotide sequences represented by SEQ ID No 18084 or 5096 of EP 1074 617, SEQ ID No 210 of WO 00/53756 or WO 99/46281, or SEQ ID Nos 22,23, 96 or 98 of WO 01/23523 and SEQ ID No 31 of WO 99/11293.

Also preferably, the polypeptide produced is not one with an amino acidsequence consisting of the sequence represented by any one of SEQ ID No18085 of EP 1 074 617, SEQ ID No 211 of either WO 00/53756 orWO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO 01/23523,or SEQ ID No 86 of WO 99/11293.

Methods of cultivating host cells and isolating recombinant proteins arewell known in the art. It will be appreciated that, depending on thehost cell, the ECSM1 or ECSM4 polypeptides produced may differ from thatwhich can be isolated from nature. For example, certain host cells, suchas yeast or bacterial cells, either do not have, or have different,post-translational modification systems which may result in theproduction of forms of ECSM1 or ECSM4 which may be post-translationallymodified in a different way to ECSM1 or ECSM4 isolated from nature. Inorder to obtain ECSM1 or ECSM4 which is post-translationally modified ina different way to human ECSM1 or ECSM4 it is preferred if the host cellis a non-human host cell; more preferably it is not a mammalian cell.

It is preferred that the ECSM1 or ECSM4 polypeptide is produced in aeukaryotic system, such as an insect cell.

According to a less preferred embodiment, the ECSM1 or ECSM4 polypeptidecan be produced in vitro using a commercially available in vitrotranslation system, such as rabbit reticulocyte lysate or wheatgermlysate (available from Promega). Preferably, the translation system israbbit reticulocyte lysate. Conveniently, the translation system may becoupled to a transcription system, such as the TNTtranscription-translation system (Promega). This system has theadvantage of producing suitable mRNA transcript from an encoding DNApolynucleotide in the same reaction as the translation. Conveniently,where the expressed polypeptide comprises one or more transmembranedomains, the translation system can be supplemented with a source ofendoplasmic reticulum-derived membranes and folding chaperones, such asdog pancreatic microsomes, to allow synthesis of the polypeptide in anative conformation.

Preferably, the production method of this aspect of the inventioncomprises a further step of isolating the ECSM1 or ECSM4 produced fromthe host cell or from the in vitro translation mix. Preferably, theisolation employs an antibody which selectively binds the expressedpolypeptide of the invention.

It will be understood that the invention comprises the ECSM1 or ECSM4polypeptides or the variants or fragments or fusions thereof, or afusion of said variants or fragments obtainable by the methods hereindisclosed, provided that the ECSM4 polypeptide is not one which consistsof the amino acid sequence given in FIG. 4. Preferably, the polypeptideis not one which consists of an amino acid sequence represented by anyone of SEQ ID No 18085 of EP 1 074 617, SEQ ID No 211 of either WO00/53756 or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO01/23523, or SEQ ID No 86 of WO 99/11293. Preferably, the ECSM1polypeptide produced by the methods herein disclosed is not one which isencoded by SEQ ID No 32 of WO 99/06423 or encoded by the nucleic acid ofATCC deposit No.209145 made on Jul. 17 1997 for the purposes of WO99/06423.

An eighteenth aspect of the invention provides an antibody capable ofselectively binding to either ECSM4 or ECSM1 as defined above.

Preferably, an antibody which selectively binds ECSM1 is not one whichbinds a polypeptide encoded by SEQ ID No 32 of WO 99/06423 or encoded bythe nucleic acid of ATCC deposit No 209145 made on Jul. 17 1997 for thepurposes of the international patent application PCT/US98/15949.

Preferably, an antibody which selectively binds ECSM1 is one which bindsa polypeptide whose amino acid sequence comprises the sequence given inFIG. 2 or a natural variant thereof but does not comprise the amino acidsequence encoded by ATCC deposit No 209145 made on Jul. 17 1997.

Preferably, an antibody which selectively binds ECSM4 is one which bindsa polypeptide whose amino acid sequence comprises the sequence given inany one of FIGS. 4, 5, 7, 12 or 13 or a natural variant thereof but doesnot bind the polypeptide represented by any one of SEQ ID No 18085 of EP1 074 617, SEQ ID No 211 of either WO 00/53756 or WO99/46281, SEQ ID Nos24-27, 29, 30, 33, 34, 38 or 39 of WO 01/23523, or SEQ ID No 86 of WO99/11293, or encoded by any one of the nucleotide sequences representedby SEQ ID No 18084 or 5096 of EP 1 074 617, SEQ ID No 210 of WO 00/53756or WO 99/46281, or SEQ ID Nos 22, 23, 96 or 98 of WO 01/23523 and SEQ IDNo 31 of WO 99/11293.

By “selectively bind” we include antibodies which bind at least 10-foldmore strongly to a polypeptide of the invention (such as ECSM4 or ECSM1)than to another polypeptide; preferably at least 50-fold more stronglyand more preferably at least 100-fold more strongly. Such antibodies maybe made by methods well known in the art using the informationconcerning the differences in amino acid sequence of ECSM4 or ECSM1 andanother polypeptide which is not a polypeptide of the invention.

Antibodies which selectively bind ECSM4 may also modulate the functionof the ECSM4 polypeptide. Antibodies which mimic the effect of bindingof the cognate ligand by stimulating or activating ECSM4, or which bindand thereby prevent subsequent binding and activation or stimulation ofECSM4 by the cognate ligand, and such function-modulating antibodies areincluded in the scope of the invention. It will be appreciated thatantibodies which modulate the function are useful as a tool in research,for example in studying the effects of ECSM4 stimulation or activation,or downstream processes triggered by such stimulation. Such antibodiesare also useful in medicine, for example in modulating angiogenesis inan individual. Specifically, modulation of angiogenesis byadministration of such an antibody may be useful in the treatment of adisease in an individual where modulation of angiogenesis would bebeneficial, such as cancer.

The following peptides may be useful as immunogens in the generation ofantibodies, such as rabbit polyclonal sera: LSQSPGAVPQALVAWRA (SEQ IDNO:6), DSVLTPEEVALCLEL (SEQ ID NO:7), TYGYISVPTA (SEQ ID NO:8) andKGGVLLCPPRPCLTPT (SEQ ID NO:9).

In a preferred embodiment of this aspect, the antibody of the inventionselectively binds an amino acid sequence with the sequence GGDSLLGGRGSL(SEQ ID NO:1), LLQPPARGHAHDGQALSTDL (SEQ ID NO:2), EPQDYTEPVE (SEQ IDNO:3), TAPGGQGAPWAEE (SEQ ID NO:4) or ERATQEPSEHGP (SEQ ID NO:5). Thesesequences represent amino acid sequences which are not identical betweenthe human and mouse ECSM4 polypeptide sequences. Generally, the humanand mouse ECSM4 polypeptides display a high degree of identity, whichmakes the production of mouse antibodies to the human ECSM4 particularlydifficult due to the lack of immunogenicity of much of the human ECSM4sequence in mouse. Amino acid sequences which are absent from the mouseECSM4 are more likely to more be immunogenic in a mouse than thosesequences which are present in the mouse ECSM4 (an alignment of thehuman and mouse ECSM4 amino acid sequences is shown in FIG. 14). Hence,polypeptide fragments which contain sequences which are unique to humanECSM4 as described above are more useful than ECSM4 polypeptides whosesequence is found in both human and mouse ECSM4, in the production ofantibodies which selectively bind the human ECSM4 polypeptide.

Antibodies generated as a result of use of amino acid sequences whichare located in the extracellular portion of the ECSM4 polypeptide arelikely to be useful as endothelial cell targeting molecules. Therefore,it is particularly preferred if the antibody of the invention is raisedto, and preferably selectively binds, an amino acid sequence which isunique to the human ECSM4 polypeptide, which sequence is located towardsthe N-terminal end of the polypeptide and is found in the extracellularportion located between residues 1 and 467 of the amino acid sequencegiven in FIG. 12. An example of an amino acid sequence which is suitablefor raising antibody molecules selective for the ECSM4 extracellularregion is given in FIG. 12.

Although the amino acid sequences which are unique to the human ECSM4may be used to produce polyclonal antibodies, it is preferred if theyare used to produce monoclonal antibodies.

Peptides in which one or more of the amino acid residues are chemicallymodified, before or after the peptide is synthesised, may be usedproviding that the function of the peptide, namely the production ofspecific antibodies in vivo, remains substantially unchanged. Suchmodifications included forming salts with acids or bases, especiallyphysiologically acceptable organic or in organic acids and bases,forming an ester or amid of a terminal carboxyl group, and attachingamino acid protecting groups such as N-t-butoxycarbonyl. Suchmodifications may protect the peptide from in vivo metabolism. Thepeptides may be present as single copies or as multiples, for exampletandem repeats. Such tandem or multiple repeats may be sufficientlyantigenic themselves to obviate the use of a carrier. It may beadvantageous for the peptide to be formed as a loop, with the N-terminaland C-terminal ends joined together, or to add one or more Cys residuesto an end to increase antigenicity and/or to allow disulphide bonds tobe formed. If the peptide is covalently linked to a carrier, preferablya polypeptide, then the arrangement is preferably such that the peptideof the invention forms a loop.

According to current immunological theories, a carrier function shouldbe present in any immunogenic formulation in order to stimulate, orenhance stimulation of, the immune system. It is though that the bestcarriers embody (or, together with the antigen, create) a T-cellepitope. The peptides may be associated, for example by cross-linking,with a separate carrier, such as serum albumins, myoglobins, bacterialtoxoids and keyhole limpit haemocyanin. More recently developed carrierswhich induce T-cell help in the immune response include the hepatitis-Bcore antigen (also called the nucleocapsid protein), presumed T-cellepitopes such as Thr-Ala-Ser-Gly-Val-Ala-Glu-Thr-Thr-Asn-Cys,β-galactosidase and the 163-171 peptide of interleukin-1. The lattercompound may variously be regarded as a carrier or as an adjuvant or asboth. Alternatively, several copies of the same or different peptides ofthe invention may be cross-linked to one another; in this situationthere is no separate carrier as such, but a carrier function may beprovided by such cross-6linking. Suitably cross-linking agents includethose listed as such in the Sigma and Pierce catalogues, for exampleglutaraldehyde, carbodiimide and succinimidyl4-(N-maleimidomethyl)cyclohexane-1-carboxylate, the latter agentexploiting the —SH group on the C-terminal cysteine residue (ifpresent).

If the peptide is prepared by expression of a suitable nucleotidesequence in a suitable host, then it may be advantageous to express thepeptide as a fusion product with a peptide sequence which acts as acarrier. Kabigen's “Ecosec” system is an example of such an arrangement.

Peptides may be synthesised by the Fmoc-polyamide mode of solid-phasepeptide synthesis as disclosed by Lu et al (1981) J. Org. Chem. 46, 3433and references therein. Temporary N-amino group protection is affordedby the 9-fluorenylmethyloxycarbonyl (Fmoc) group. Repetitive cleavage ofthis highly base-labile protecting group is effected using 20%piperidine in N,N-dimethylformamide. Side-chain functionalities may beprotected as their butyl ethers (in the case of serine threonine andtyrosine), butyl esters (in the case of glutamic acid and asparticacid), butyloxycarbonyl derivative (in the case of lysine andhistidine), trityl derivative (in the case of cysteine) and4-methoxy-2,3,6-trimethylbenzenesulphonyl derivative (in the case ofarginine). Where glutamine or asparagine are C-terminal residues, use ismade of the 4,4′-dimethoxybenzhydryl group for protection of the sidechain amido functionalities. The solid-phase support is based on apolydimethyl-acrylamide polymer constituted from the three monomersdimethylacrylamide (backbone-monomer), bisacryloylethylene diamine(cross linker) and acryloylsarcosine methyl ester (functionalisingagent). The peptide-to-resin cleavable linked agent used is theacid-labile 4-hydroxymethyl-phenoxyacetic acid derivative. All aminoacid derivatives are added as their preformed symmetrical anhydridederivatives with the exception of asparagine and glutamine, which areadded using a reversedN,N-dicyclohexyl-carbodiimide/1-hydroxybenzotriazole mediated couplingprocedure. All coupling and deprotection reactions are monitored usingninhydrin, trinitrobenzene sulphonic acid or isotin test procedures.Upon completion of synthesis, peptides are cleaved from the resinsupport with concomitant removal of side-chain protecting groups bytreatment with 95% trifluoroacetic acid containing a 50% scavenger mix.Scavengers commonly used are ethanedithiol, phenol, anisole and water,the exact choice depending on the constituent amino acids of the peptidebeing synthesised. Trifluoroacetic acid is removed by evaporation invacuo, with subsequent trituration with diethyl ether affording thecrude peptide. Any scavengers present are removed by a simple extractionprocedure which on lyophilisation of the aqueous phase affords the crudepeptide free of scavengers. Reagents for peptide synthesis are generallyavailable from Calbiochem-Novabiochem (UK) Ltd, Nottingham NG7 2QJ, UK.Purification may be effected by any one, or a combination of, techniquessuch as size exclusion chromatography, ion-exchange chromatography and(principally) reverse-phase high performance liquid chromatography.Analysis of peptides may be carried out using thin layer chromatography,reverse-phase high performance liquid chromatography, amino-acidanalysis after acid hydrolysis and by fast atom bombardment (FAB) massspectrometric analysis.

The peptide of the invention may be linked to other antigens to providea dual effect.

Included in the scope of the invention is a method of producing anantibody according to this aspect of the invention.

Antibodies can be raised in an animal by immunising with an appropriatepeptide. Appropriate peptides are described herein. Alternatively, withtoday's technology, it is possible to make antibodies as defined hereinwithout the need to use animals. Such techniques include, for example,antibody phage display technology as is well known in the art.Appropriate peptides, as described herein, may be used to selectantibodies produced in this way.

It will be appreciated that, with the advancements in antibodytechnology, it may not be necessary to immunise an animal in order toproduce an antibody. Synthetic systems, such as phage display libraries,may be used. The use of such systems is included in the methods of theinvention and the products of such systems are “antibodies” for thepurposes of the invention.

It will be appreciated that such antibodies which recognise ECSM1 orECSM4 and variants or fragments thereof are useful research reagents andtherapeutic agents, particularly when prepared as a compound of theinvention as described above. Suitably, the antibodies of the inventionare detectably labelled, for example they may be labelled in such a waythat they may be directly or indirectly detected. Conveniently, theantibodies are labelled with a radioactive moiety or a coloured moietyor a fluorescent moiety, or they may be linked to an enzyme. Typically,the enzyme is one which can convert a non-coloured (or non-fluorescent)substrate to a coloured (or fluorescent) product. The antibody may belabelled by biotin (or streptavidin) and then detected indirectly usingstreptavidin (or biotin) which has been labelled with a radioactivemoiety or a coloured moiety or a fluorescent moiety, or the like or theymay be linked to any enzyme of the type described above.

A nineteenth aspect of the invention provides a method of detectingendothelial damage or activation in an individual comprising obtaining afluid sample from the individual and detecting the presence of fragmentsof ECSM1 or ECSM4 in the sample.

Preferably, the fluid sample is blood. Typically, the presence ofpeptide fragments derived from ECSM1 or ECSM4 are detected.

In a preferred embodiment of this aspect, the presence of peptidefragments of the ECSM1 or ECSM4 polypeptides are detected using anantibody selective for a polypeptide whose amino acid sequence comprisesa sequence given in either one of FIG. 2 or FIG. 4 or FIG. 12 orfragments thereof. Preferably, the antibody is an antibody according tothe eighteenth aspect of the invention. Typically, such an antibodywould be detectably labelled.

Detecting or diagnosing endothelial cell damage in an individual isuseful in diagnosing cancer or aiding diagnosis of cardiac disease,endometriosis or artheroslcerosis in that individual. It may be thatcertain levels of apparent cell damage are detected in individuals whodo not have cancer, cardiac disease, endometriosis or artheroslcerosis.It may be necessary to compare the amount of endothelial cell damagedetected with amounts or levels observed in individuals who are known tohave cancer, cardiac disease, endometriosis or artheroslcerosis with the“normal” levels of apparent damage in the individual who does not havecancer, cardiac disease, endometriosis or artheroslcerosis.

Hence, detection of endothelial damage or activation in an individualmay be 4 useful as a means of detecting the presence or extent or growthrate of a tumour in that individual. The detection of vessel damage isan indirect report of the formation of tumour neovasculature. In thisway, ECSM4 or ECSM1 may be surrogate markers of angiogenesis. Thepresence of ECSM4 or ECSM1 fragments in a sample from the individual, ormore ECSM4 or ECSM1 polypeptide fragments than in an individual who doesnot have a tumour, may be a means of detecting a tumour, or growth of aknown tumour, in that individual.

Furthermore, it will be appreciated that detection of neovasculature bymeans of detecting the presence of, or a certain level of, ECSM4 orECSM1 in a sample from an individual may be useful in determining if atreatment in that individual is being effective, and/or to what extentthe treatment is effective. Preferably the therapy is to treat a tumouror cancer in the individual.

Hence, an aspect of the invention provides a method of detecting atumour or tumour neovasculature or cardiac disease or endometriosis orartherosclerosis in an individual comprising obtaining a fluid samplefrom the individual and detecting the presence of fragments of ECSM1 orECSM4 in the sample.

As described above in relation to detecting or diagnosing endothelialcell damage, detection of the disease (such as 4 tumour or cardiacdisease etc) by means of detecting the presence of, or a certain levelof, ECSM4 or ECSM1 in a sample from an individual may be useful indetermining the efficacy of a treatment in that individual.

In one embodiment, the therapy is gene therapy.

Preferably, the efficacy of the a treatment in an individual isdetermined using the amount of fragments of ECSM1 or ECSM4 found in thefluid sample of the individual and comparing it to either to the amountof ECSM1 or ECSM4 fragments in a sample from an individual who does nothave cancer, cardiac disease, endometriosis oil artherosclerosis and/orto the amount in a sample from the individual prior to commencement ofsaid treatment The comparison indicates the efficacy of treatment of theindividual, wherein if there is no change in the amount of fragmentsdetermined before and during/after treatment this is indicative of poorefficacy of the treatment. A decrease in the amount of fragments foundduring or after treatment compared to the amount found before treatmentwas started indicates some efficacy of the treatment in ameliorating thecondition of the individual.

Current methods of assessing the efficacy of various anti-angiogenictherapies being tested in clinical trials are invasive. The selectiveexpression of ECSM4 on endothelial cells of angiogenic blood vesselsmeans that detecting the presence, absence, increase or decrease in thelevel of ECSM1 or ECSM4 in a subject undergoing therapy is a means ofdetermining the efficacy of the therapy in that subject without theneed, or with a reduced need, for invasive biopsies, scans and the suchlike.

Hence, determination of the level of ECSM1 and or ECSM4 fragments in theblood of an individual undergoing an anti-angiogenic therapy (such ascancer therapy) may act as a “surrogate marker of angiogenesis”.

By “peptide fragments derived from ECSM1 or ECSM4” we mean peptideswhich have at least 5 consecutive amino acids of the ECSM4 or ECSM1polypeptide. Typically, the fragments have at least 8 consecutive aminoacids, preferably at least 10, more preferably at least 12 or 15 or 20or 30 or 40 or 50 consecutive amino acids of the ECSM4 or ECSM1polypeptide.

Methods for detecting the presence of fragments of peptides derived fromlarger polypeptides are known in the art.

A further aspect of the invention provides a method of modulatingangiogenesis in an individual, the method comprising administering tothe individual ESCM4 or a peptide fragment of ECSM4 or a ligand of ECSM4or an antibody which selectively binds to ECSM4 or ECSM1.

Preferably, the peptide fragment or ligand or antibody is one whichmodulates the activity or function, either directly or indirectly, ofthe ECSM4 polypeptide of the individual.

Preferred antibodies are those as described in more detail above.

The production of antibodies which modulate the function of apolypeptide exposed on the cell surface is known in the art and isdiscussed in more detail above. Such antibodies may modulate thefunction by imitating the function of the natural ligand and stimulatingthe polypeptide into activity or function, or may modulate thepolypeptide function by preventing stimulation of the polypeptide by theligand by sterically obscuring the ligand binding site therebypreventing binding of the natural ligand.

Delivery of a ligand to magic roundabout might be an angiogenicinhibitor useful in therapy of cancer or other diseases involvinghyper-angiogenesis. Also, introduction of the ECSM4 polypeptide toendothelial cells by gene therapy using the ECSM4 encodingpolynucleotide might alter growth and migration.

A still further aspect of the invention provides a method of diagnosinga condition which involves aberrant or excessive growth of vascularendothelium in an individual comprising obtaining a sample containingnucleic acid from the individual and contacting said sample with apolynucleotide which selectively hybridises to a nucleic acid whichencodes the ECSM4 polypeptide or the ECSM1 polypeptide or a fragment ornatural variant thereof.

The method may be used for aiding diagnosis.

A condition which involves aberrant or excessive growth of vascularendothelium such as cancer, artherosclerosis, restenosis, diabeticretinopathy, arthritis, psoriasis, endometriosis, menorrhagia,haemangiomas and venous malformations may be caused by a mutation in thenucleic acid which encodes the ECSM1 or ECSM4 polypeptides.

By “selectively hybridising” is meant that the nucleic acid hassufficient nucleotide sequence similarity with the said human DNA orcDNA that it can hybridise under moderately or highly stringentconditions. As is well known in the art, the stringency of nucleic acidhybridization depends on factors such as length of nucleic acid overwhich hybridisation occurs, degree of identity of the hybridizingsequences and on factors such as temperature, ionic strength and CG orAT content of the sequence. Thus, any nucleic acid which is capable ofselectively hybridising as said is useful in the practice of theinvention.

Nucleic acids which can selectively hybridise to the said human DNA orcDNA include nucleic acids which have >95% sequence identity, preferablythose with >98%, more preferably those with >99% sequence identity, overat least a portion of the nucleic acid with the said human DNA or cDNA.As is well known, human genes usually contain introns such that, forexample, a mRNA or cDNA derived from a gene within the said human DNAwould not match perfectly along its entire length with the said humanDNA but would nevertheless be a nucleic acid capable of selectivelyhybridising to the said human DNA. Thus, the invention specificallyincludes nucleic acids which selectively hybridise to an ECSM4 or ECSM1cDNA but may not hybridise to an ECSM4 or ECSM1 gene, or vice versa. Forexample, nucleic acids which span the intron-exon boundaries of theECSM4 or ECSM1 gene may not be able to selectively hybridise to theECSM4 or ECSM1 cDNA.

Typical moderately or highly stringent hybridisation conditions whichlead to selective hybridisation are known in the art, for example thosedescribed in Molecular Cloning, a laboratory manual, 2nd edition,Sambrook et al (eds), Cold Spring Harbor Laboratory Press, Cold SpringHarbor, N.Y., USA, incorporated herein by reference.

An example of a typical hybridisation solution when a nucleic acid isimmobilised on a nylon membrane and the probe nucleic acid is ≧500 basesor base pairs is:

-   -   6×SSC (saline sodium citrate)    -   0.5% sodium dodecyl sulphate (SDS)    -   100 μg/ml denatured, fragmented salmon sperm DNA

The hybridisation is performed at 68° C. The nylon membrane, with thenucleic acid immobilised, may be washed at 68° C. in 1×SSC or, for highstringency, 0.1×SSC.

20×SSC may be prepared in the following way. Dissolve 175.3 g of NaCland 88.2 g of sodium citrate in 800 ml of H₂O. Adjust the pH to 7.0 witha few drops of a 10 N solution of NaOH. Adjust the volume to 1 litrewith H₂O. Dispense into aliquots. Sterilize by autoclaving.

An example of a typical hybridisation solution when a nucleic acid isimmobilised on a nylon membrane and the probe is an oligonucleotide ofbetween 15 and 50 bases is:

-   -   3.0 M trimethylammonium chloride (TMACl)    -   0.01 M sodium phosphate (pH 6.8)    -   1 mm EDTA (pH 7.6)    -   0.5% SDS    -   100 μg/ml denatured, fragmented salmon sperm DNA    -   0.1% nonfat dried milk

The optimal temperature for hybridization is usually chosen to be 5° C.below the T_(i) for the given chain length. T_(i) is the irreversiblemelting temperature of the hybrid formed between the probe and itstarget sequence. Jacobs et al (1988) Nucl. Acids Res. 16, 4637 discussesthe determination of T_(i)s. The recommended hybridization temperaturefor 17-mers in 3 M TMACl is 48-50° C.; for 19-mers, it is 55-57° C.; andfor 20-mers, it is 58-66° C.

By “nucleic acid which selectively hybridises” is also included nucleicacids which will amplify DNA from the said region of human DNA by any ofthe well known amplification systems such as those described in moredetail below, in particular the polymerase chain reaction (PCR).Suitable conditions for PCR amplification include amplification in asuitable 1× amplification buffer:

10× amplification buffer is 500 mM KCl; 100 mM Tris.Cl (pH 8.3 at roomtemperature); 15 mM MgCl₂; 0.1% gelatin.

A suitable denaturing agent or procedure (such as heating to 95° C.) isused in order to separate the strands of double-stranded DNA.

Suitably, the annealing part of the amplification is between 37° C. and60° C., preferably 50° C.

Although the nucleic acid which is useful in the methods of theinvention may be RNA or DNA, DNA is preferred. Although the nucleic acidwhich is useful in the methods of the invention may be double-strandedor single-stranded, single-stranded nucleic acid is preferred under somecircumstances such as in nucleic acid amplification reactions.

The sample may be directly derived from the patient, for example, bybiopsy of a tissue which may be associated with aberrant vasculardevelopment, or it may be derived from the patient from a site remotefrom the tissue, for example because cells from the tissue have migratedfrom the tissue to other parts of the body. Alternatively, the samplemay be indirectly derived from the patient in the sense that, forexample, the tissue or cells therefrom may be cultivated in vitro, orcultivated in a xenograft model; or the nucleic acid sample may be onewhich has been replicated (whether in vitro or in vivo) from nucleicacid from the original source from the patient. Thus, although thenucleic acid derived from the patient may have been physically withinthe patient, it may alternatively have been copied from nucleic acidwhich was physically within the patient. When aberrant vasculardevelopment is believed to be associated with a tumour, tumour tissuemay be taken from the primary tumour or from metastases.

It will be appreciated that a useful method of the invention includesthe analysis of mutations in, or the detection of the presence orabsence of, the ECSM4 or ECSM1 gene in any suitable sample. The samplemay suitably be a freshly-obtained sample from the patient, or thesample may be an historic sample, for example a sample held in a libraryof samples.

Conveniently, the nucleic acid capable of selectively hybridising to thesaid human DNA and which is used in the methods of the invention furthercomprises a detectable label.

By “detectable label” is included any convenient radioactive label suchas ³²P, ³³P or ³⁵S which can readily be incorporated into a nucleic acidmolecule using well known methods; any convenient fluorescent orchemilumninescent label which can readily be incorporated into a nucleicacid is also included. In addition the term “detectable label” alsoincludes a moiety which can be detected by virtue of binding to anothermoiety (such as biotin which can be detected by binding tostreptavidin); and a moiety, such as an enzyme, which can be detected byvirtue of its ability to convert a colourless compound into a colouredcompound, or vice versa (for example, alkaline phosphatase can convertcolourless o-nitrophenylphosphate into coloured o-nitrophenol).Conveniently, the nucleic acid probe may occupy a certain position in afixed assay and whether the nucleic acid hybridises to the said regionof human DNA can be determined by reference to the position ofhybridisation in the fixed assay. The detectable label may also be afluorophore-quencher pair as described in Tyagi & Kramer (1996) NatureBiotechnology 14, 303-308.

Conveniently, in this method of diagnosis of a condition in whichvascular development is aberrant the nucleic acid which is capable ofthe said selective hybridisation (whether labelled with a detectablelabel or not) is contacted with a nucleic acid derived from the patientunder hybridising conditions. Suitable hybridising conditions includethose described above.

This method of diagnosing a condition in which vascular development isaberrant may involve sequencing of DNA at one or more of the relevantpositions within the relevant region, including direct sequencing;direct sequencing of PCR-amplified exons; differential hybridisation ofan oligonucleotide probe designed to hybridise at the relevant positionswithin the relevant region (conveniently this uses immobilisedoligonucleotide probes in, so-called, “chip” systems which are wellknown in the art); denaturing gel electrophoresis following digestionwith an appropriate restriction enzyme, preferably followingamplification of the relevant DNA regions; S1 nuclease sequenceanalysis; non-denaturing gel electrophoresis, preferably followingamplification of the relevant DNA regions; conventional RFLP(restriction fragment length polymorphism) assays; heteroduplexanalysis; selective DNA amplification using oligonucleotides;fluorescent in-situ hybridisation (FISH) of interphase chromosomes;ARMS-PCR (Amplification Refractory Mutation System-PCR) for specificmutations; cleavage at mismatch sites in hybridised nucleic acids (thecleavage being chemical or enzymic); SSCP single strand conformationalpolymorphism or DGGE (discontinuous or denaturing gradient gelelectrophoresis); analysis to detect mismatch in annealed normal/mutantPCR-amplified DNA; and protein truncation assay (translation andtranscription of exons—if a mutation introduces a stop codon a truncatedprotein product will result). Other methods may be employed such asdetecting changes in the secondary structure of single-stranded DNAresulting from changes in the primary sequence, for example, using thecleavase I enzyme. This system is commercially available from GibcoBRL,Life Technologies, 3 Fountain Drive, Inchinnan Business Park, PaisleyPA4 9RF, Scotland.

It will be appreciated that the methods of the invention may also becarried out on “DNA chips”. Such “chips” are described in U.S. Pat. No.5,445,934 (Affymetrix; probe arrays), WO 96/31622 (Oxford; probe arrayplus ligase or polymerase extension), and WO 95/22058 (Afymax;fluorescently marked targets bind to oligomer substrate, and location inarray detected); all of these are incorporated herein by reference.

Detailed methods of mutation detection are described in “LaboratoryProtocols for Mutation Detection” 1996, ed. Landegren, Oxford UniversityPress on behalf of HUGO (Human Genome Organisation).

It is preferred if RFLP is used for the detection of fairly large (≧500bp) deletions or insertions. Southern blots may be used for this methodof the invention.

PCR amplification of smaller regions (maximum 300 bp) to detect smallchanges greater than 3-4 bp insertions or deletions may be preferred.Amplified sequence may be analysed on a sequencing gel, and smallchanges (minimum size 3-4 bp) can be visualised. Suitable primers aredesigned as herein described.

In addition, using either Southern blot analysis or PCR restrictionenzyme variant sites may be detected. For example, for analysing variantsites in genomic DNA restriction enzyme digestion, gel electrophoresis,Southern blotting, and hybridisation specific probe (for example anysuitable fragment derived from the ECSM4 or ECSM1 cDNA or gene).

For example, for analysing variant sites using PCR DNA amplification,restriction enzyme digestion, gel detection by ethidium bromide, silverstaining or incorporation of radionucleotide or fluorescent primer inthe PCR.

Other suitable methods include the development of allele specificoligonucleotides (ASOs) for specific mutational events. Similar methodsare used on RNA and cDNA for the suitable tissue.

Whilst it is useful to detect mutations in any part of the ECSM4 orECSM1 gene, it is preferred if the mutations are detected in the exonsof the gene and it is further preferred if the mutations are ones whichchange the coding sense. The detection of these mutations is a preferredaspect of the invention.

The methods of the invention also include checking forloss-of-heterozygosity (LOH; shows one copy lost). LOH may be asufficient marker for diagnosis; looking for mutation/loss of the secondallele may not be necessary. LOH of the gene may be detected usingpolymorphisms in the coding sequence, and introns, of the gene.

Particularly preferred nucleic acids for use in the aforementionedmethods of the invention are those selected from the group consisting ofprimers suitable for amplifying nucleic acid.

Suitably, the primers are selected from the group consisting of primerswhich hybridise to the nucleotide sequences shown in any of the FIGS.which show ECSM4 or ECSM1 gene or cDNA sequences. It is particularlypreferred if the primers hybridise to the introns of the ECSM4 or ECSM1gene or if the primers are ones which will prime synthesis of DNA fromthe ECSM4 or ECSM1 gene or cDNA but not from other genes or cDNAs.

Primers which are suitable for use in a polymerase chain reaction (PCR;Saiki et al (1988) Science 239, 487-491) are preferred. Suitable PCRprimers and methods of detecting products of PCR reactions are describedin detail above.

Any of the nucleic acid amplification protocols can be used in themethod of the invention including the polymerase chain reaction, QBreplicase and ligase chain reaction. Also, NASBA (nucleic acid sequencebased amplification), also called 3SR, can be used as described inCompton (1991) Nature 350, 91-92 and AIDS (1993), Vol 7 (Suppl 2), S108or SDA (strand displacement amplification) can be used as described inWalker et al (1992) Nucl. Acids Res. 20, 1691-1696. The polymerase chainreaction is particularly preferred because of its simplicity.

The present invention provides the use of a nucleic acid whichselectively hybridises to the human-derived DNA of genomic clones asdescribed in Table 8 of Example 1 or to the ECSM4 or ECSM1 gene, or amutant allele thereof, or a nucleic acid which selectively hybridises toECSM4 or ECSM1 cDNA or a mutant allele thereof, or their complement in amethod of diagnosing a condition in which vascular development isaberrant; or in the manufacture of a reagent for carrying out thesemethods.

Preferred polynucleotides which selectively hybridise to the ECSM4 geneor cDNA are as described above in relation to a method of diagnosis.

Also, the present invention provides a method of determining thepresence or absence, or mutation in, the said ECSM4 or ECSM1 gene.Preferably, the method uses a suitable sample from a patient.

The methods of the invention include the detection of mutations in theECSM4 or ECSM1 gene.

The methods of the invention may make use of a difference in restrictionenzyme cleavage sites caused by mutation. A non-denaturing gel may beused to detect differing lengths of fragments resulting from digestionwith an appropriate restriction enzyme.

An “appropriate restriction enzyme” is one which will recognise and cutthe wild-type sequence and not the mutated sequence or vice versa. Thesequence which is recognised and cut by the restriction enzyme (or not,as the case may be) can be present as a consequence of the mutation orit can be introduced into the normal or mutant allele using mismatchedoligonucleotides in the PCR reaction. It is convenient if the enzymecuts DNA only infrequently, in other words if it recognises a sequencewhich occurs only rarely.

In another method, a pair of PCR primers are used which match (iehybridise to) either the wild-type genotype or the mutant genotype butnot both. Whether amplified DNA is produced will then indicate thewild-type or mutant genotype (and hence phenotype). However, this methodrelies partly on a negative result (ie the absence of amplified DNA)which could be due to a technical failure. It therefore may be lessreliable and/or requires additional control experiments.

A preferable method employs similar PCR primers but, as well ashybridising to only one of the wild-type or mutant sequences, theyintroduce a restriction site which is not otherwise there in either thewild-type or mutant sequences.

The nucleic acids which selectively hybridise to the ECSM4 or ECSM1 geneor cDNA, or which selectively hybridise to the genomic clones containingECSM4 or ECSM1 as listed in Table 8 of Example 1 are useful for a numberof purposes. They can be used in Southern hybridization to genomic DNAand in the RNase protection method for detecting point mutations alreadydiscussed above. The probes can be used to detect PCR amplificationproducts. They may also be used to detect mismatches with the ECSM4 orECSM1 gene or mRNA in a sample using other techniques. Mismatches can bedetected using either enzymes (eg S1 nuclease or resolvase), chemicals(eg hydroxylamine or osmium tetroxide and piperidine), or changes inelectrophoretic mobility of mismatched hybrids as compared to totallymatched hybrids. These techniques are known in the art. Generally, theprobes are complementary to the ECSM4 or ECSM1 gene coding sequences,although probes to certain introns are also contemplated. A battery ofnucleic acid probes may be used to compose a kit for detecting loss ofor mutation in the wild-type ECSM4 or ECSM1 gene. The kit allows forhybridization to the entire ECSM4 or ECSM1 gene. The probes may overlapwith each other or be contiguous.

If a riboprobe is used to detect mismatches with mRNA, it iscomplementary to the mRNA of the human ECSM4 or ECSM1 gene. Theriboprobe thus is an anti-sense probe in that it does not code for theprotein encoded by the ECSM4 or ECSM1 gene because it is of the oppositepolarity to the sense strand. The riboprobe generally will be labelled,for example, radioactively labelled which can be accomplished by anymeans known in the art. If the riboprobe is used to detect mismatcheswith DNA it can be of either polarity, sense or anti-sense. Similarly,DNA probes also may be used to detect mismatches.

Nucleic acid probes may also be complementary to mutant alleles of theECSM4 or ECSM1 gene. These are useful to detect similar mutations inother patients on the basis of hybridization rather than mismatches. Asmentioned above, the ECSM4 or ECSM1 gene probes can also be used inSouthern hybridizations to genomic DNA to detect gross chromosomalchanges such as deletions and insertions.

Particularly useful methods of detecting a mutation in the ECSM1 orECSM4 genes include single strand conformation polymorphism (SSCP),hetero duplex analysis, polymerase chain reaction, using DNA chips andsequencing.

Any sample containing nucleic acid derived from the individual is usefulin the methods of the invention. It is preferred if the nucleic acid inthe sample is DNA. Thus, samples from cells may be obtained as is wellknown in the art, for example from blood samples or cheek cells or thelike. Where the methods are being used to determine the presence orabsence of a mutation in an unborn child, it is preferred if the sampleis a maternal sample containing nucleic acid from the unborn child.Suitable maternal samples include the amniotic fluid of the mother,chorionic villus samples and blood samples from which foetal cells canbe isolated.

A further aspect of the invention provides a method of reducing theexpression of the ECSM4 or ECSM1 polynucleotide in an individual,comprising administering to the individual an agent which selectivelyprevents expression of ECSM4 or ECSM1.

In a preferred embodiment, the agent which selectively preventsexpression of ECSM4 or ECSM1 is an antisense nucleic acid.

Preferably, the antisense nucleic acid is not one (or is not antisenseto one) whose sequence consists of the sequence represented by SEQ ID No18084 or 5096 of EP 1 074 617, SEQ ID No 210 of WO 00/53756 or WO99/46281, or SEQ ID Nos 22, 23, 96 or 98 of WO 01/23523 or SEQ ID No 31of WO 99/11293 or their complement, or a nucleic acid sequence whichencodes a polypeptide whose amino acid sequence is represented by anyone of SEQ ID No 18085 of EP 1 074 617, SEQ ID. No 211 of either WO00/53756 or WO99/46281, SEQ ID Nos 24-27, 29, 30, 33, 34, 38 or 39 of WO01/23523, or SEQ ID No 86 of WO 99/11293.

A further aspect thereof includes administering an antisense nucleicacid to a cell in order to prevent expression of ECSM4 or ECSM1.Typically, the cell is in the body of an individual in need ofprevention of expression of ESCM4 or ECSM1.

The ECSM4 or ECSM1 polynucleotide which is bound by an antisensemolecule may be DNA or RNA.

Preferred antisense molecules are as described above.

Diseases which may be treated by reducing ECSM4 or ECSM1 expressioninclude diseases involving aberrant or excessive vascularisation asdescribed above.

Antisense nucleic acids are well known in the art and are typicallysingle-stranded nucleic acids, which can specifically bind to acomplementary nucleic acid sequence. By binding to the appropriatetarget sequence, an RNA-RNA, a

DNA-DNA, or RNA-DNA duplex is formed. These nucleic acids are oftentermed “antisense” because they are complementary to the sense or codingstrand of the gene. Recently, formation of a triple helix has provenpossible where the oligonucleotide is bound to a DNA duplex. It wasfound that oligonucleotides could recognise sequences in the majorgroove of the DNA double helix. A triple helix was formed thereby. Thissuggests that it is possible to synthesise a sequence-specific moleculeswhich specifically bind double-stranded DNA via recognition of majorgroove hydrogen binding sites.

By binding to the target nucleic acid, the above oligonucleotides caninhibit the function of the target nucleic acid. This could, forexample, be a result of blocking the transcription, processing,poly(A)addition, replication, translation, or promoting inhibitorymechanisms of the cells, such as promoting RNA degradations.

Antisense oligonucleotides are prepared in the laboratory and thenintroduced into cells, for example by microinjection or uptake from thecell culture medium into the cells, or they are expressed in cells aftertransfection with plasmids or retroviruses or other vectors carrying anantisense gene. Antisense oligonucleotides were first discovered toinhibit viral replication or expression in cell culture for Rous sarcomavirus, vesicular stomatitis virus, herpes simplex virus type 1, simianvirus and influenza virus. Since then, inhibition of mRNA translation byantisense oligonucleotides has been studied extensively in cell-freesystems including rabbit reticulocyte lysates and wheat germ extracts.Inhibition of viral function by antisense oligonucleotides has beendemonstrated in vitro using oligonucleotides which were complementary tothe AIDS HIV retrovirus RNA (Goodchild, J. 1988 “Inhibition of HumanImmunodeficiency Virus Replication by Antisense Oligodeoxynucleotides”,Proc. Natl. Acad. Sci. (USA) 85(15), 5507-11). The Goodchild studyshowed that oligonucleotides that were most effective were complementaryto the poly(A) signal; also effective were those targeted at the 5′ endof the RNA, particularly the cap and 5′ untranslated region, next to theprimer binding site and at the primer binding site. The cap, 5′untranslated region, and poly(A) signal lie within the sequence repeatedat the ends of retrovirus RNA (R region) and the oligonucleotidescomplementary to these may bind twice to the RNA.

Typically, antisense oligonucleotides are 15 to 35 bases in length. Forexample, 20-mer oligonucleotides have been shown to inhibit theexpression of the epidermal growth factor receptor mRNA (Witters et al,Breast Cancer Res Treat 53:41-50 (1999)) and 25-mer oligonucleotideshave been shown to decrease the expression of adrenocorticotropichormone by greater than 90% (Frankel et al, J Neurosurg 91:261-7(1999)). However, it is appreciated that it may be desirable to useoligonucleotides with lengths outside this range, for example 10, 11,12, 13, or 14 bases, or 36, 37, 38, 39 or 40 bases.

Oligonucleotides are subject to being degraded or inactivated bycellular endogenous nucleases. To counter this problem, it is possibleto use modified oligonucleotides, eg having altered intemucleotidelinkages, in which the naturally occurring phosphodiester linkages havebeen replaced with another linkage. For example, Agrawal et al (1988)Proc. Natl. Acad. Sci. USA 85, 7079-7083 showed increased inhibition intissue culture of HIV-1 using oligonucleotide phosphoramidates andphosphorothioates. Sarin et al (1988) Proc. Natl. Acad. Sci. USA 85,7448-7451 demonstrated increased inhibition of HIV-1 usingoligonucleotide methylphosphonates. Agrawal et al (1989) Proc. Natl.Acad. Sci. USA 86, 7790-7794 showed inhibition of HIV-1 replication inboth early-infected and chronically infected cell cultures, usingnucleotide sequence-specific oligonucleotide phosphorothioates. Leitheret al (1990) Proc. Natl. Acad. Sci. USA 87, 3430-3434 report inhibitionin tissue-culture of influenza virus replication by oligonucleotidephosphorothioates.

Oligonucleotides having artificial linkages have been shown to beresistant to degradation in vivo. For example, Shaw et al (1991) inNucleic Acids Res. 19, 747-750, report that otherwise unmodifiedoligonucleotides become more resistant to nucleases in vivo when theyare blocked at the 3′ end by certain capping structures and thatuncapped oligonucleotide phosphorothioates are not degraded in vivo.

A detailed description of the H-phosphonate approach to synthesizingoligonucleoside phosphorothioates is provided in Agrawal and Tang (1990)Tetrahedron Letters 31, 7541-7544, the teachings of which are herebyincorporated herein by reference. Syntheses of oligonucleosidemethylphosphonates, phosphorodithioates, phosphoramidates, phosphateesters, bridged phosphoramidates and bridge phosphorothioates are knownin the art See, for example, Agrawal and Goodchild (1987) TetrahedronLetters 28, 3539; Nielsen et al (1988) Tetrahedron Letters 29, 2911;Jager et al (1988) Biochemistry 27, 7237; Uznanski et al (1987)Tetrahedron Letters 28, 3401; Bannwarth (1988) Helv. Chim. Acta. 71,1517; Crosstick and Vyle (1989) Tetrahedron Letters 30, 4693; Agrawal etal (1990) Proc. Natl Acad. Sci. USA 87, 1401-1405, the teachings ofwhich are incorporated herein by reference. Other methods for synthesisor production also are possible. In a preferred embodiment theoligonucleotide is a deoxynbonucleic acid (DNA), although ribonucleicacid (RNA) sequences may also be synthesized and applied.

The oligonucleotides useful in the invention preferably are designed toresist degradation by endogenous nucleolytic enzymes. In vivodegradation of oligonucleotides produces oligonucleotide breakdownproducts of reduced length. Such breakdown products are more likely toengage in non-specific hybridization and are less likely to beeffective, relative to their full-length counterparts. Thus, it isdesirable to use oligonucleotides that are resistant to degradation inthe body and which are able to reach the targeted cells. The presentoligonucleotides can be rendered more resistant to degradation in vivoby substituting one or more internal artificial internucleotide linkagesfor the native phosphodiester linkages, for example, by replacingphosphate with sulphur in the linkage. Examples of linkages that may beused include phosphorothioates, methylphosphonates, sulphone, sulphate,ketyl, phosphorodithioates, various phosphoramidates, phosphate esters,bridged phosphorothioates and bridged phosphoramidates. Such examplesare illustrative, rather than limiting, since other internucleotidelinkages are known in the art. See, for example, Cohen, (1990) Trends inBiotechnology. The synthesis of oligonucleotides having one or more ofthese linkages substituted for the phosphodiester intemucleotidelinkages is well known in the art, including synthetic pathways forproducing oligonucleotides having mixed intemucleotide linkages.

Oligonucleotides can be made resistant to extension by endogenousenzymes by “capping” or incorporating similar groups on the 5′ or 3′terminal nucleotides. A reagent for capping is commercially available asAmino-Link II™ from Applied BioSystems Inc, Foster City, Calif. Methodsfor capping are described, for example, by Shaw et al (1991) NucleicAcids Res. 19, 747-750 and Agrawal et al (1991) Proc. Natl. Acad. SciUSA 88(17), 7595-7599, the teachings of which are hereby incorporatedherein by reference.

A further method of making oligonucleotides resistant to nuclease attackis for them to be “self-stabilized” as described by Tang et al (1993)Nucl. Acids Res. 21, 2729-2735 incorporated herein by reference.Self-stabilized oligonucleotides have hairpin loop structures at their3′ ends, and show increased resistance to degradation by snake venomphosphodiesterase, DNA polymerase I and fetal bovine serum. Theself-stabilized region of the oligonucleotide does not interfere inhybridization with complementary nucleic acids, and pharmacokinetic andstability studies in mice have shown increased in vivo persistence ofself-stabilized oligonucleotides with respect to their linearcounterparts.

In accordance with the invention, the antisense compound may beadministered systemically. Alternatively the inherent bindingspecificity of antisense oligonucleotides characteristic of base pairingis enhanced by limiting the availability of the antisense compound toits intended locus in vivo, permitting lower dosages to be used andminimising systemic effects. Thus, oligonucleotides may be appliedlocally to achieve the desired effect The concentration of theoligonucleotides at the desired locus is much higher than if theoligonucleotides were administered systemically, and the therapeuticeffect can be achieved using a significantly lower total amount. Thelocal high concentration of oligonucleotides enhances penetration of thetargeted cells and effectively blocks translation of the target nucleicacid sequences.

The oligonucleotides can be delivered to the locus by any meansappropriate for localised administration of a drug. For example, asolution of the oligonucleotides can be injected directly to the site orcan be delivered by infusion using an infusion pump. Theoligonucleotides also can be incorporated into an implantable devicewhich when placed at the desired site, permits the oligonucleotides tobe released into the surrounding locus.

The oligonucleotides may be administered via a hydrogel material. Thehydrogel is non-inflammatory and biodegradable. Many such materials noware known, including those made from natural and synthetic polymers. Ina preferred embodiment, the method exploits a hydrogel which is liquidbelow body temperature but gels to form a shape-retaining semisolidhydrogel at or near body temperature. Preferred hydrogel are polymers ofethylene oxide-propylene oxide repeating units. The properties of thepolymer are dependent on the molecular weight of the polymer and therelative percentage of polyethylene oxide and polypropylene oxide in thepolymer. Preferred hydrogels contain from about 10% to about 80% byweight ethylene oxide and from about 20% to about 90% by weightpropylene oxide. A particularly preferred hydrogel contains about 70%polyethylene oxide and 30% polypropylene oxide. Hydrogels which can beused are available, for example, from BASF Corp., Parsippany, N.J.,under the tradename Pluronic®.

In this embodiment, the hydrogel is cooled to a liquid state and theoligonucleotides are admixed into the liquid to a concentration of about1 mg oligonucleotide per gram of hydrogel. The resulting mixture then isapplied onto the surface to be treated, for example by spraying orpainting during surgery or using a catheter or endoscopic procedures. Asthe polymer warms, it solidifies to form a gel, and the oligonucleotidesdiffuse out of the gel into the surrounding cells over a period of timedefined by the exact composition of the gel.

It will be appreciated that the oligonucleotides or other agents may beadministered after surgical removal of a tumour, and may be administeredto the area from which the tumour has been removed, and surroundingtissue, for example using cytoscopy to guide application of theoligonucleotides or other agents.

The oligonucleotides can be administered by means of other implants thatare commercially available or described in the scientific literature,including liposomes, microcapsules and implantable devices. For example,implants made of biodegradable materials such as polyanhydrides,polyorthoesters, polylactic acid and polyglycolic acid and copolymersthereof, collagen, and protein polymers, or non-biodegradable materialssuch as ethylenevinyl acetate (EVAc), polyvinyl acetate, ethylene vinylalcohol, and derivatives thereof can be used to locally deliver theoligonucleotides. The oligonucleotides can be incorporated into thematerial as it is polymerised or solidified, using melt or solventevaporation techniques, or mechanically mixed with the material. In oneembodiment, the oligonucleotides are mixed into or applied onto coatingsfor implantable devices such as dextran coated silica beads, stents, orcatheters.

The dose of oligonucleotides is dependent on the size of theoligonucleotides and the purpose for which is it administered. Ingeneral, the range is calculated based on the surface area of tissue tobe treated. The effective dose of oligonucleotide is somewhat dependenton the length and chemical composition of the oligonucleotide but isgenerally in the range of about 30 to 3000 μg per square centimetre oftissue surface area.

The oligonucleotides may be administered to the patient systemically forboth therapeutic and prophylactic purposes. The oligonucleotides may beadministered by any effective method, for example, parenterally (egintravenously, subcutaneously, intramuscularly) or by oral, nasal orother means which permit the oligonucleotides to access and circulate inthe patients bloodstream. Oligonucleotides administered systemicallypreferably are given in addition to locally administeredoligonucleotides, but also have utility in the absence of localadministration. A dosage in the range of from about 0.1 to about 10grams per administration to an adult human generally will be effectivefor this purpose.

It will be appreciated that antisense agents also include largermolecules which bind to said ECSM4 or ECSM1 mRNA or genes andsubstantially prevent expression of said ECSM4 or ECSM1 mRNA or genesand substantially prevent expression of said ECSM4 or ECSM1 protein.Thus, expression of an antisense molecule which is substantiallycomplementary to said ECSM4 or ECSM1 mRNA is envisaged as part of theinvention.

The said larger molecules may be expressed from any suitable geneticconstruct as is described below and delivered to the patient. Typically,the genetic construct which expresses the antisense molecule comprisesat least a portion of the said ECSM4 or ECSM1 cDNA or gene operativelylinked to a promoter which can express the antisense molecule in a cell.Promoters that may be active in endothelial cells are described below.

Although the genetic construct can be DNA or RNA it is preferred if itis DNA.

Preferably, the genetic construct is adapted for delivery to a humancell.

Means and methods of introducing a genetic construct into a cell in ananimal body are known in the art. For example, the constructs of theinvention may be introduced into proliferating endothelial cells by anyconvenient method, for example methods involving retroviruses, so thatthe construct is inserted into the genome of the endothelial cell. Forexample, in Kuriyama et al (1991) Cell Struc. and Func. 16, 503-510purified retroviruses are administered. Retroviruses provide a potentialmeans of selectively infecting proliferating endothelial cells becausethey can only integrate into the genome of dividing cells; mostendothelial cells are in a quiescent, non-receptive stage of cell isgrowth or, at least, are dividing much less rapidly than angiogeniccells. Retroviral DNA constructs which encode said antisense agents maybe made using methods well known in the art. To produce activeretrovirus from such a construct it is usual to use an ecotropic psi2packaging cell line grown in Dulbecco's modified Eagle's medium (DMEM)containing 10% foetal calf serum (FCS). Transfection of the cell line isconveniently by calcium phosphate co-precipitation, and stabletransformants are selected by addition of G418 to a final concentrationof 1 mg/ml (assuming the retroviral construct contains a neo® gene).Independent colonies are isolated and expanded and the culturesupernatant removed, filtered through a 0.45 μm pore-size filter andstored at −70°. For the introduction of the retrovirus into the tumourcells, it is convenient to inject directly retroviral supernatant towhich 10 μmg/ml Polybrene has been added. For tumours exceeding 10 mm indiameter it is appropriate to inject between 0.1 ml and 1 ml ofretroviral supernatant; preferably 0.5 ml.

Alternatively, as described in Culver et al (1992) Science 256,1550-1552, cells which produce retroviruses are injected into specifictissue. The retrovirus-producing cells so introduced are engineered toactively produce retroviral vector particles so that continuousproductions of the vector occurred within the tumour mass in situ. Thus,proliferating endothelial cells can be successfully transduced in vivoif mixed with retroviral vector-producing cells.

Targeted retroviruses are also available for use in the invention; forexample, sequences conferring specific binding affinities may beengineered into pre-existing viral env genes (see Miller & Vile (1995)Faseb J. 9, 190-199 for a review of this and other targeted vectors forgene therapy).

Other methods involve simple delivery of the construct into the cell forexpression therein either for a limited time or, following integrationinto the genome, for a longer time. An example of the latter approachincludes (preferably endothelial-cell-targeted) liposomes (Nässander etal (1992) Cancer Res. 52, 646-653).

Immunoliposomes (antibody-directed liposomes) are especially useful intargeting to endothelial cell types which express a cell surface proteinfor which antibodies are available.

Other methods of delivery include adenoviruses carrying external DNA viaan antibody-polylysine bridge (see Curiel Prog. Med. Virol. 40, 1-18)and transferrin-polycation conjugates as carriers (Wagner et al (1990)Proc. Natl. Acad. Sci. USA 87, 3410-3414). In the first of these methodsa polycation-antibody complex is formed with the DNA construct or othergenetic construct of the invention, wherein the antibody is specific foreither wild-type adenovirus or a variant adenovirus in which a newepitope has been introduced which binds the antibody. The polycationmoiety binds the DNA via electrostatic interactions with the phosphatebackbone. The adenovirus, because it contains unaltered fibre and pentonproteins, is internalised into the cell and carries into the cell withit the DNA construct of the invention. It is preferred if the polycationis polylysine.

The DNA may also be delivered by adenovirus wherein it is present withinthe adenovirus particle, for example, as described below.

In the second of these methods, a high-efficiency nucleic acid deliverysystem that uses receptor-mediated endocytosis to carry DNAmacromolecules into cells is employed. This is accomplished byconjugating the iron-transport protein transferrin to polycations thatbind nucleic acids. Human transferrin, or the chicken homologueconalbumin, or combinations thereof is covalently linked to the smallDNA-binding protein protamine or to polylysines of various sizes througha disulfide linkage. These modified transferrin molecules maintain theirability to bind their cognate receptor and to mediate efficient irontransport into the cell. The transferrin-polycation molecules formelectrophoretically stable complexes with DNA constructs or othergenetic constructs of the invention independent of nucleic acid size(from short oligonucleotides to DNA of 21 kilobase pairs). Whencomplexes of transferrin-polycation and the DNA constructs or othergenetic constructs of the invention are supplied to the endothelialcells, a high level of expression from the construct in the cells isexpected.

High-efficiency receptor-mediated delivery of the DNA constructs orother genetic constructs of the invention using the endosome-disruptionactivity of defective or chemically inactivated adenovirus particlesproduced by the methods of Cotten et al (1992) Proc. Natl. Acad. Sci.USA 89, 6094-6098 may also be used. This approach appears to rely on thefact that adenoviruses are adapted to allow release of their DNA from anendosome without passage through the lysosome, and in the presence of,for example transferrin linked to the DNA construct or other geneticconstruct of the invention, the construct is taken up by the cell by thesame route as the adenovirus particle.

This approach has the advantages that there is no need to use complexretroviral constructs; there is no permanent modification of the genomeas occurs with retroviral infection; and the targeted expression systemis coupled with a targeted delivery system, thus reducing toxicity toother cell types.

It may be desirable to locally perfuse a tumour with the suitabledelivery vehicle comprising the genetic construct for a period of time;additionally or alternatively the delivery vehicle or genetic constructcan be injected directly into accessible tumours.

It will be appreciated that “naked DNA” and DNA complexed with cationicand neutral lipids may also be useful in introducing the DNA of theinvention into cells of the patient to be treated. Non-viral approachesto gene therapy are described in Ledley (1995) Human Gene Therapy 6,1129-1144.

Alternative targeted delivery systems are also known such as themodified adenovirus system described in WO 94/10323 wherein, typically,the DNA is carried within the adenovirus, or adenovirus-like, particle.Michael et al (1995) Gene Therapy 2, 660-668 describes modification ofadenovirus to add a cell-selective moiety into a fibre protein.; Mutantadenoviruses which replicate selectively in p53-deficient human tumourcells, such as those described in Bischoff et al (1996) Science 274,373-376 are also useful for delivering the genetic construct of theinvention to a cell. Thus, it will be appreciated that a further aspectof the invention provides a virus or virus-like particle comprising agenetic construct of the invention. Other suitable viruses or virus-likeparticles include HSV, AAV, vaccinia and parvovirus.

In a further embodiment the agent which selectively prevents thefunction of ECSM4 or ECSM1 is a ribozyme capable of cleaving targetedECSM4 or ECSM1 RNA or DNA. A gene expressing said nbozyme may beadministered in substantially the same and using substantially the samevehicles as for the antisense molecules.

Ribozymes which may be encoded in the genomes of the viruses orvirus-like particles herein disclosed are described in Cech andHerschlag “Site-specific cleavage of single stranded DNA” U.S. Pat. No.5,180,818; Altman et al “Cleavage of targeted RNA by RNAse P” U.S. Pat.No. 5,168,053, Cantin et al “Ribozyme cleavage of HIV-1 RNA” U.S. Pat.No. 5,149,796; Cech et al “RNA ribozyme restriction endoribonucleasesand methods”, U.S. Pat. No. 5,116,742; Been et al “RNA ribozymepolymerases, dephosphorylases, restriction endonucleases and methods”,U.S. Pat. No. 5,093,246; and Been et al “RNA ribozyme polymerases,dephosphorylases, restriction endonbonucleases and methods; cleavessingle-stranded RNA at specific site by transesterification”, U.S. Pat.No. 4,987,071, all incorporated herein by reference.

It will be appreciated that it may be desirable that the antisensemolecule or ribozyme is expressed from a cell-specific promoter element.

The genetic constructs of the invention can be prepared using methodswell known in the art.

A further aspect of the invention is a method of screening for amolecule that binds to ECSM4 or a suitable variant, fragment or fusionthereof, or a fusion of a said fragment or fusion thereof, the methodcomprising 1) contacting a) the ECSM4 polypeptide with b) a testmolecule 2) detecting the presence of a complex containing the ECSM4polypeptide and a test molecule, and optionally 3) identifying any testmolecule bound to the ECSM4 polypeptide.

Preferably the ECSM4 polypeptide is one as described above in respect ofthe eleventh aspect of the invention.

In a preferred embodiment, the test molecule is a polypeptide.

In a further preferred embodiment, the method is used to identifynatural ligands of ECSM4. Thus, in this embodiment the test moleculeincludes the natural ligand of ECSM4. A particularly useful techniquefor the identification of natural ligands of polypeptide molecules isthe yeast two-hybrid technique. This technique is well known in the artand relies on binding between a molecule and its cognate ligand to bringtogether two parts of a transcription complex (which are fused one tothe molecule in question and other to the test ligand) which, whentogether, promote transcription of a reporter gene.

Hence, a preferred embodiment of this aspect of the invention comprisesuse of the screening method, preferably the yeast two-hybrid system, toidentify natural ligands of the ECSM4 polypeptide.

A molecule which is identifiable as binding the ECSM4 polypeptide is afurther aspect of the invention.

It will be appreciated that a molecule which binds to ESCM4 may modulatethe activation of ECSM4.

Suitable peptide ligands that will bind to ECSM4 may be identified usingmethods known in the art.

One method, disclosed by Scott and Smith (1990) Science 249, 386-390 andCwirla et al (1990) Proc. Natl. Acad. Sci. USA 87, 6378-6382, involvesthe screening of a vast library of filamentous bacteriophages, such asM13 or fd, each member of the library having a different peptide fusedto a protein on the surface of the bacteriophage. Those members of thelibrary that bind to ECSM4 are selected using an iterative bindingprotocol, and once the phages that bind most tightly have been purified,the sequence of the peptide ligands may be determined simply bysequencing the DNA encoding the surface protein fusion. Another methodthat can be used is the NovaTope (TM) system commercially available fromNovagen, Inc., 597 Science Drive, Madison, Wis. 53711. The method isbased on the creation of a library of bacterial clones, each of whichstably expresses a small peptide derived from a candidate protein inwhich the ligand is believed to reside. The library is screened bystandard lift methods using the antibody or other binding agent as aprobe. Positive clones can be analysed directly by DNA sequencing todetermine the precise amino acid sequence of the ligand.

Further methods using libraries of beads conjugated to individualspecies of peptides as disclosed by Lam et al (1991) Nature 354, 82-84or synthetic peptide combinatorial libraries as disclosed by Houghten etal (1991) Nature 354, 84-86 or matrices of individual synthetic peptidesequences on a solid support as disclosed by Pirrung et al in U.S. Pat.No. 5,143,854 may also be used to identify peptide ligands.

It will be appreciated that screening assays which are capable of highthroughput operation will be particularly preferred. Examples mayinclude cell based assays and protein-protein binding assays. AnSPA-based (Scintillation Proximity Assay; Amersbam International) systemmay be used. For example, an assay for identifying a compound capable ofmodulating the activity of a protein kinase may be performed as follows.Beads comprising scintillant and a polypeptide that may bephosphorylated may be prepared. The beads may be mixed with a samplecomprising the protein kinase and ³²P-ATP or ³³P-ATP and with the testcompound. Conveniently this is done in a 96-well format. The plate isthen counted using a suitable scintillation counter, using knownparameters for 32P or ³³P SPA assays. Only ³²P or ³³P that is inproximity to the scintillant, i.e. only that bound to the polypeptide,is detected. Variants of such an assay, for example in which thepolypeptide is immobilised on the scintillant beads via binding to anantibody, may also be used.

Other methods of detecting polypeptide/polypeptide interactions includeultrafiltration with ion spray mass spectroscopy/HPLC methods or otherphysical and analytical methods. Fluorescence Energy Resonance Transfer(FRET) methods, for example, well known to those skilled in the art, maybe used, in which binding of two fluorescent labelled entities may bemeasured by measuring the interaction of the fluorescent labels when inclose proximity to each other.

Alternative methods of detecting binding of a polypeptide tomacromolecules, for example DNA, RNA, proteins and phospholipids,include a surface plasmon resonance assay, for example as described inPlant et al (1995) Analyt Biochem 226(2), 342-348. Methods may make useof a polypeptide that is labelled, for example with a radioactive orfluorescent label.

A further method of identifying a compound that is capable of binding tothe ECSM4 polypeptide is one where the polypeptide is exposed to thecompound and any binding of the compound to the said polypeptide isdetected and/or measured. The binding constant for the binding of thecompound to the polypeptide may be determined. Suitable methods fordetecting and/or measuring (quantifying) the binding of a compound to apolypeptide are well known to those skilled in the art and may beperformed, for example, using a method capable of high throughputoperation, for example a chip-based method. New technology, calledVLSIPS™, has enabled the production of extremely small chips thatcontain hundreds of thousands or more of different molecular probes.These biological chips or arrays have probes arranged in arrays, eachprobe assigned a specific location. Biological chips have been producedin which each location has a scale of, for example, ten microns. Thechips can be used to determine whether target molecules interact withany of the probes on the chip. After exposing the array to targetmolecules under selected test conditions, scanning devices can examineeach location in the array and determine whether a target molecule hasinteracted with the probe at that location.

Biological chips or arrays are useful in a variety of screeningtechniques for obtaining information about either the probes or thetarget molecules. For example, a library of peptides can be used asprobes to screen for drugs. The peptides can be exposed to a receptor,and those probes that bind to the receptor can be identified. See U.S.Pat. No. 5,874,219 issued Feb. 23, 1999 to Rava et al.

Another method of targeting proteins that modulate the activity of ECSM4is the yeast two-hybrid system, where the polypeptides of the inventioncan be used to “capture” ECSM4 protein binding proteins. The yeasttwohybrid system is described in Fields & Song, Nature 340:245-246(1989).

It will be understood that it will be desirable to identify compoundsthat may modulate the activity of the polypeptide in vivo. Thus it willbe understood that reagents and conditions used in the method may bechosen such that the interactions between the said and the interactingpolypeptide are substantially the same as between a said naturallyoccurring polypeptide and a naturally occurring interacting polypeptidein vivo.

It will be appreciated that in the method described herein, the ligandmay be a drug-like compound or lead compound for the development of adrug-like compound.

The term “drug-like compound” is well known to those skilled in the art,and may include the meaning of a compound that has characteristics thatmay make it suitable for use in medicine, for example as the activeingredient in a medicament. Thus, for example, a drug-like compound maybe a molecule that may be synthesised by the techniques of organicchemistry, less preferably by techniques of molecular biology orbiochemistry, and is preferably a small molecule, which may be of lessthan 5000 daltons and which may be water-soluble. A drug-like compoundmay additionally exhibit features of selective interaction with aparticular protein or proteins and be bioavailable and/or able topenetrate target cellular membranes, but it will be appreciated thatthese features are not essential.

The term “lead compound” is similarly well known to those skilled in theart, and may include the meaning that the compound, whilst not itselfsuitable for use as a drug (for example because it is only weakly potentagainst its intended target, non-selective in its action, unstable,poorly soluble, difficult to synthesise or has poor bioavailability) mayprovide a starting-point for the design of other compounds that may havemore desirable characteristics.

Alternatively, the methods may be used as “library screening” methods, aterm well known to those skilled in the art. Thus, for example, themethod of the invention may be used to detect (and optionally identify)a polynucleotide capable of expressing a polypeptide activator of ECSM4.Aliquots of an expression library in a suitable vector may be tested forthe ability to give the required result.

Hence, an embodiment of this aspect of the invention provides a methodof identifying a drug-like compound or lead compound for the developmentof a drug-like compound that modulates the activity of the polypeptideECSM4, the method comprising contacting a compound with the polypeptideor a suitable variant, fragment, derivative or fusion thereof or afusion of a variant, fragment or derivative thereof and determiningwhether, for example, the enzymic activity of the said polypeptide ischanged compared to the activity of the said polypeptide or saidvariant, fragment, derivative or fusion thereof or a fusion of avariant, fragment or derivative thereof in the absence of said compound.

Preferably, the ECSM4 polypeptide is as described above in respect ofthe eleventh aspect of the invention.

It will be understood that it will be desirable to identify compoundsthat may modulate the activity of the polypeptide in vivo. Thus it willbe understood that reagents and conditions used in the method may bechosen such that the interactions between the said polypeptide and itssubstrate are substantially the same as in vivo.

In one embodiment, the compound decreases the activity of saidpolypeptide. For example, the compound may bind substantially reversiblyor substantially irreversibly to the active site of said polypeptide. Ina further example, the compound may bind to a portion of saidpolypeptide that is not the active site so as to interfere with thebinding of the said polypeptide to its ligand. In a still furtherexample, the compound may bind to a portion of said polypeptide so as todecrease said polypeptide's activity by an allosteric effect. Thisallosteric effect may be an allosteric effect that is involved in thenatural regulation of the said polypeptide's activity, for example inthe activation of the said polypeptide by an “upstream activator”.

A still further aspect of the invention provides a polynucleotidecomprising a promoter and/or regulatory portion of any one of the ECSM1or ECSM4 genes.

By “ECSM1 or ECSM4 genes” we mean the natural genomic sequence whichwhen transcribed is capable of encoding a polypeptide comprising theECSM1 or ECSM4 polypeptide sequence as defined herein. The naturalgenomic sequence of the ECSM1 or ECSM4 genes may contain introns.

The polynucleotide of this aspect of the invention is preferably onewhich has transcriptional promoter activity. A promoter is an expressioncontrol element formed by a DNA sequence that permits binding of RNApolymerase and transcription to occur. Preferably the transcriptionalpromoter activity is present in mammalian cells and more preferably thepolynucleotide has transcriptional promoter activity in endothelialcells. In a preferred embodiment, the transcriptional promoter activityis present in endothelial cells and not in other cell types.

Preferably, the promoter and/or regulatory portion is one which candirect endothelial cell selective expression.

Preferably, the promoter or regulatory region of the ECSM4 gene is onewhich is capable of promoting transcription of an operatively-linkedcoding sequence in response to hypoxic conditions. More preferably, thelevel of transcription of the coding sequence is up-regulated in hypoxicconditions compared to the level of transcription in the absence ofhypoxia. By “hypoxic conditions” we include the physiological conditionsof cancer where the inappropriate cell proliferation deprivessurrounding tissue of oxygen, cardiac disease where for example a vesselocclusion may restrict the delivery of oxygen to certain tissues, andtissue necrosis where destruction of vascular tissue cells results in areduced supply of oxygen to surrounding tissue and the consequent deathof that surrounding tissue. Hypoxia is described in more detail inHockel and Vaupel (2001) J. Nat. Can. Inst. 93: 266-276.

Hence, in a preferred embodiment, the ECSM4 promoter or regulatoryregion is comprised in a vector suitable for use in gene therapy fordriving expression of a therapeutic gene to treat a hypoxic condition.Preferably, the hypoxic condition is cancer or cardiac disease. A“therapeutic gene” may be any gene which provides a desired therapeuticeffect.

It will be appreciated that use of the said ECSM4 promoter to treat ahypoxic condition, for example by gene therapy, is included within thescope of the present invention.

Methods for the determination of the sequence of the promoter region ofa gene are well known in the art. The presence of a promoter region maybe determined by identification of known motifs, and confirmed bymutational analysis of the identified sequence. Preferably, the promotersequence is located in the region 5 kb upstream of the genomic codingregion of ECSM 1 or ECSM4. More preferably, it is located in the region3 kb or 2 kb or 1 kb or 500 bp upstream, and still more preferably it islocated within 210 bp of the transcription start site.

Regulatory regions, or transcriptional elements such as enhancers areless predictable than promoters in their location relative to a gene.However, many motifs indicative of regulatory regions are wellcharacterised and such regions affecting the level of transcription ofthe relevant gene can usually be identified on the basis of thesemotifs. The function of such a region can be demonstrated by well-knownmethods such as mutational analysis and in vitro DNA-binding assaysincluding DNA footprinting and gel mobility shift assays.

Regulatory regions influencing the transcription of the ECSM1 or ECSM4genes are likely to be located within the region 20 kb or 10 kb or 7 kb5 kb or 3 kb, or more preferably 1 kb 5′ upstream of the relevantgenomic coding region or can be located within introns of the gene.

Sequence tagged sites and mapping intervals will be helpful inlocalising promoter regions, regulatory regions and physical clones.

In a further preferred embodiment, the polynucleotide comprising thepromoter and/or regulatory portion is operatively linked to apolynucleotide encoding a polypeptide. Methods for linking promoterpolynucleotides to polypeptide coding sequences are well known in theart.

Preferably the polypeptide is a therapeutic polypeptide. A therapeuticpolypeptide may be any polypeptide which it is medically useful toexpress selectively in endothelial cells. Examples of such therapeuticpolypeptides include anti-proliferative, immunomodulatory or bloodclotting-influencing factors, or anti-proliferative or anti-inflammatorycytokines. They may also comprise anti-cancer polypeptides.

In one embodiment of this aspect of the invention, the polynucleotide isone suitable for use in medicine. Thus, the invention includes thepolynucleotide packaged and presented for use in medicine. It will beappreciated that such polynucleotides will be especially useful in genetherapy, especially where it is desirable to express a therapeuticpolypeptide selectively an endothelial cell. It is preferred if thepolynucleotide is one suitable for use in gene therapy.

Gene therapy may be carried out according to generally accepted methods,for example, as described by Friedman, 1991. A virus or plasmid vector(see further details below), containing a copy of the gene to beexpressed linked to expression control elements such as promoters andother regulatory elements influencing transcription of ECSM1 or ECSM4 asdescribed above and capable of replicating inside endothelial cells, isprepared. Suitable vectors are known, such as disclosed in U.S. Pat. No.5,252,479 and WO 93/07282. The vector is then injected into the patient,either locally or systemically. If the transfected gene is notpermanently incorporated into the genome of each of the targetedendothelial cells, the treatment may have to be repeated periodically.

Gene transfer systems known in the art may be useful in the practice ofthe gene therapy methods of the present invention. These include viraland nonviral transfer methods. A number of viruses have been used asgene transfer vectors, including papovaviruses, eg SV40 (Madzak et al,1992), adenovirus (Berkner, 1992; Berkner et al, 1988; Gorziglia andKapikian, 1992; Quantin et al, 1992; Rosenfeld et al, 1992; Wilkinson etal, 1992; Stratford-Perricaudet et al, 1990), vaccinia virus (Moss,1992), adeno-associated virus (Muzyczka, 1992; Ohi et al, 1990),herpesviruses including HSV and EBV (Margolskee, 1992; Johnson et al,1992; Fink et al, 1992; Breakfield and Geller, 1987; Freese et al,1990), and retroviruses of avian (Brandyopadhyay and Temin, 1984;Petropoulos et al, 1992), mutine (Miller, 1992; Miller et al, 1985;Sorge et al, 1984; Mann and Baltimore, 1985; Miller et al, 1988), andhuman origin (Shimada et al, 1991; Helseth et al, 1990; Page et al,1990; Buchschacher and Panganiban, 1992). To date most human genetherapy protocols have been based on disabled murine retroviruses.

Nonviral gene transfer methods known in the art include chemicaltechniques such as calcium phosphate coprecipitation (Graham and van derEb, 1973; Pellicer et al, 1980); mechanical techniques, for examplemicroinjection (Anderson et al, 1980; Gordon et al, 1980; Brinster etal, 1981; Constantini and Lacy, 1981); membrane fusion-mediated transfervia liposomes (Felgner et al, 1987; Wang and Huang, 1989; Kaneda et al,1989; Stewart et al, 1992; Nabel et al, 1990; Lim et al, 1992); anddirect DNA uptake and receptor-mediated DNA transfer (Wolff et al, 1990;Wu et al, 1991; Zenke et al, 1990; Wu et al, 1989b; Wolff et al, 1991;Wagner et al, 1990; Wagner et al, 1991; Cotten et al, 1990; Curiel etal, 1991a; Curiel et al, 1991b).

Other suitable systems include the retroviral-adenoviral hybrid systemdescribed by Feng et al (1997) Nature Biotechinology 15, 866-870, orviral systems with targeting ligands such as suitable single chain Fvfragments.

In an approach which combines biological and physical gene transfermethods, plasmid DNA of any size is combined with apolylysine-conjugated antibody specific to the adenovirus hexon protein,and the resulting. complex is bound to an adenovirus vector. Thetrimolecular complex is then used to infect cells. The adenovirus vectorpermits efficient binding, internalization, and degradation of theendosome before the coupled DNA is damaged.

Liposome/DNA complexes have been shown to be capable of mediating directin vivo gene transfer. While in standard liposome preparations the genetransfer process is nonspecific, localized in vivo uptake and expressionhave been reported in tumour deposits, for example, following direct insitu administration (Nabel, 1992).

Gene transfer techniques which target DNA directly to tissues, egendothelial cells, is preferred. Receptor-mediated gene transfer, forexample, is accomplished by the conjugation of DNA (usually in the formof covalently closed supercoiled plasmid) to a protein ligand viapolylysine. Ligands are chosen on the basis of the presence of thecorresponding ligand receptors on the cell surface of the targetcell/issue type. In the case of endothelial cells, a suitable receptoris ECSM4. These ligand-DNA conjugates can be injected directly into theblood if desired and are directed to the target tissue where receptorbinding and internalization of the DNA-protein complex occurs. Toovercome the problem of intracellular destruction of DNA, coinfectionwith adenovirus can be included to disrupt endosome function.

In the case where replacement gene therapy using a functionallywild-type gene is used, it may be useful to monitor the treatment bydetecting the presence of replacement gene mRNA or encoded replacementpolypeptide, or functional gene product, at various sites in the body,including the endothelial cells, blood serum, and bodilysecretions/excretions, for example urine.

A further aspect of the present invention provides a method of treatingan individual with cancer, cardiac disease, a hypoxic condition,endometriosis or artherosclerosis comprising administering to theindividual a polynucleotide according to the invention, whichpolynucleotide comprises a promoter or regulatory region of theinvention operatively linked to a polynucleotide encoding a therapeuticpolypeptide.

A still further aspect of the invention provides a method of modulatingangipgenesis in an individual comprising administering to the individuala polynucleotide according to the invention, which polynucleotidecomprises a promoter or regulatory region of the invention operativelylinked to a polynucleotide encoding a therapeutic polypeptide or apolynucleotide which is capable of expressing ECSM4 or a fragment orvariant thereof or which comprises an ECSM4 antisense nucleic acid.

The therapeutic polypeptide may be any therapeutic polypeptide which isuseful in treating the individual. Preferably, the therapeuticpolypeptide is any one or more of immunomodulatory, anti-cancer, ablood-clotting-influencing factor or an anti-proliferative oranti-inflammatory cytoline.

Antisense nucleic acid is discussed in more detail above. Briefly, thefunction of an antisense nucleic acid is to inhibit the translation of aspecific mRNA to which the antisense nucleic acid is complementary andable to hybridise to within a cell, at least in part. The design ofoptimal antisense nucleic acid molecules is well known in the art ofmolecular biology.

The present invention also provides a use of a polynucleotide accordingto the invention, which polynucleotide comprises a promoter orregulatory region of the invention operatively linked to apolynucleotide encoding a therapeutic polypeptide in the manufacture ofa medicament for treating cancer, cardiac disease, a bypoxic condition,endometriosis or artherosclerosis.

The invention will now be described in more detail by reference to thefollowing Examples and Figures herein

FIG. 1.

Experimental verification by reverse transcription PCR. Candidateendothelial specific genes predicted by the combination of theUniGene/EST screen and xProfiler SAGE differential analysis (Table 8)were checked for expression in three endothelial and ninenon-endothelial cell cultures. Endothelial cultures were as follows:HMVEC (human microvascular endothelial cells), HUVEC (human umbilicalvein endothelial cells) confluent culture and HUVEC proliferatingculture. Non-endothelial cultures were as follows: normal endometrialstromal (NES) cells grown in normoxia and NES grown in hypoxia, MDA 453and MDA 468 breast carcinoma cell lines, HeLa, FEK4 fibroblasts culturedin normoxia and FEK4 fibroblasts cultured in hypoxia, and SW480,HCT116—two colorectal epithelium cell lines. ECSM1 showed completeendothelial specificity, while magic roundabout/ECSM4 was very stronglypreferentially expressed in the endothelium. Interestingly, both thesenovel genes appear more endothelial specific than the benchmarkendothelial specific gene: von Willebrand factor.

FIG. 2.

Phrap generated contig sequence for ECSM1 and amino acid sequence of thetranslation product. The ESTs used to generate this contig are shown inTable 10.

FIG. 3.

ECSM4 in vitro transcription/translation. The cDNA coding for fulllength ECSM4 was cloned into pBluescript plasmid vector. Circular andHindIII digested plasmid were subjected to in vitrotranscription/translation using TNT® T7 Quick CoupledTranscription/Translation System (Promega Corporation) incorporating ³⁵SMethionine as per manufacturer's instructions. The reaction productswere resolved by SDS PAGE and visualised by autoradiography. TheLuciferase plasmid was utilised as a positive control for the reaction.The numbers on the left indicate the position of molecular size markersfor reference. The size of the band denoting ECSM4 is consistent withthe calculated molecular weight of the polypeptide of 118 kDa.

FIG. 4.

cDNA and computer translation of GenBank AK000805 (human ECSM4/magicroundabout (SEQ ID NOs:23 and 24).

FIG. 5.

Phrap generated contig sequence for human ECSM4 (magic roundabout) ESTs(SEQ ID NO:25) and translation of the encoded polypeptide (SEQ IDNO:26). The DNA sequence is shown in the orientation as if it were acDNA, which is opposite to that in which it was originally generated.The ESTs used to generate the contig are shown in Table 11. Translationstart in this sequence is at position 2 of the contig sequence, andtranslation finish is at position 948.

FIG. 6.

An alignment of the GenBank Accession No AK000805 (“magic.seq”) (SEQ IDNO:27) and Phrap (“hs.111518”) generated nucleic acid sequences of humanECSM4 (SEQ ID NO:28) given in FIGS. 4 and 5.

FIG. 7.

Mouse ECSM4 contig nucleotide sequence (SEQ ID NO:29) and amino acidsequence (SEQ ID NO:30).

FIG. 8.

An alignment of the amino acid sequences of the mouse Robo1 protein(“T30805”) (SEQ ID NO:32) and human ECSM4 (“magic.pep”) (SEQ ID NO:31).

FIG. 9.

An alignment of the amino acid sequences of mouse Robo1 protein(“T30805” ) (SEQ ID NO:33) and mouse ECSM4 (“mousemagic.pep”) (SEQ IDNO:30).

FIG. 10.

An alignment of the amino acid sequences of human (“magic.pep”) (SEQ IDNO:35) and mouse (“mousemagic.pep”) ECSM4 proteins (SEQ ID NO:34).Residues in bold indicate well conserved sequences. The mouse proteinsequence is shown on top and the human sequence is below.

FIG. 11.

Expression of magic roundabout in vitro. (a) Ribonuclease protectionanalysis. Top, two probes to different regions (nucleotides 1 to 355 and3333 to 3679) of magic roundabout were used in the analysis (shown leftand right). RNase protection assay was performed with U6 small nuclearRNA as control (shown bottom) (Maxwell et al (1999) Nature 399: 271).Human cell lines and primary isolates: MRC-5, fibroblast cell line,MCF-7, breast carcinoma cell line, Neuro, SY-SH-5Y neuroblastoma cellline, HUVEC, umbilical vein endothelial isolate, HDMEC, dermalmicrovascular endothelial isolate and HMME2, mammary microvascularendothelial cell line. N, normoxia, H, hypoxia, P, proliferating. (b)Western analysis of cell lysates. A band at ˜110 kD corresponds to MRand was stronger in cells exposed to hypoxia for 18 h. The experimentwas repeated twice with similar results. Immunoblotting was carried outas described in Brown et al (2000) Cancer Res. 60: 6298. Polyclonalrabbit anti-sera was raised against the following peptides coupled tokeyhole limpet haemocyanin: amino acids 165-181 (LSQSPGAVPQALVAWRA;SEQID NO:6) and 274-288 (DSVLTPEEVALCLEL; SEQ ID NO:7) (anti-sera 1) orpeptides 311-320 (TYGYISVPTA; SEQ ID NO:8) and 336-351(KGGVLLCPPRPCLTPT; SEQ ID NO:9) (anti-sera 2). Both anti-sera gaveidentical results. For western analysis, anti-sera was affinity purifiedon a “Hi-Trap NHS-activated HP” column (Amersham) to which the peptidesused to raise anti-sera 1 were coupled.

FIG. 12.

Human ECSM4 full-length cDNA (SEQ ID NO:36) and encoded protein sequence(SEQ ID NO:37).

FIG. 13.

Mouse ECSM4 full-length cDNA (MuMR.seq) (SEQ ID NOs:38 and 39) andencoded protein sequences (SEQ ID NOs:40-42).

FIG. 14.

Alignment of human ECSM4 (top) (SEQ ID NO:43) and mouse ECSM4 (bottom)amino acid sequences (SEQ ID NO:48) and (SEQ ID NOs:45-47).

FIG. 15.

Alignment of human ECSM4 (“HuMR.seq”; top (SEQ ID NO:49)) and mouseECSM4 (“MuMR.seq”; bottom (SEQ ID NO50)) cDNA sequences.

FIG. 16.

In situ hybridisation-analysis of human placental tissue using ECSM4 asprobe. A bright field view of 10× magnification of thin section ofplacental tissue. The arrow indicates a large blood vessel.

FIG. 17.

In situ hybridisation analysis of human placental tissue using ECSM4 asprobe. A higher magnification of the bright-field view of thin sectionof placental tissue shown in FIG. 16, focussing on the blood vessel. Thearrow points to endothelial cells lining the lumen of the vessel.

FIG. 18.

In situ hybridisation analysis of human placental tissue using ECSM4 asprobe. A higher magnification of the thin section of placental tissueshown in FIG. 16, focussing on the blood vessel and shown here indark-field. The arrow depicts positive staining of endothelial cellslining the lumen of the vessel.

FIG. 19.

In situ hybridisation analysis of colorectal liver metastatic tissueusing ECSM4 as probe. A bright-field view of a section of colorectalliver metastatic tissue magnified with (A) 10× and (B) 20× objective.The area marked by the boundary (encircling * A) depicts the normalliver tissue. The arrow in (B) shows one of the blood vessels within themetastatic tumour tissue.

FIG. 20.

In situ hybridisation analysis of colorectal liver metastatic tissueusing ECSM4 as a probe. This is a dark field view of a section ofcolorectal liver metastatic tissue magnified with (A) 10× and (B) 20×objective. The area marked by the boundary (encircling *) depicts thenormal liver tissue. The arrow in (13) shows one of the blood vesselswithin the metastatic tumour tissue corresponding to the vessel shown inFIG. 19B. Expression of ECSM4 is restricted to endothelial cells of thetumour blood vessels. Note that there is little expression in thesurrounding normal tissue (*).

FIG. 21.

Western Blot using the rabbit antibody MGO-5 as primary antibody.Dilutions of the peptides ECSM4-derived peptides MR 165, MR 311, MR 366and the control polypeptide Bovine Serum Albumin (BSA) were resolved bySDS polyacrylamide gel electrophoresis and blotted onto Immobilon Pmembrane. The blot was probed with MGO-5 antibody and visualised usinganti-rabbit antibody coupled with alkaline phosphatase.

FIG. 22.

Immunostaining of frozen placental section. A frozen thin section ofhuman placenta was analysed by immunohistochemistry without any primaryantibody (negative control) and visualised using anti-rabbit antibodycoupled with alkaline phosphatase. Little background staining isobserved.

FIG. 23.

Immunostaining of frozen placental section. A frozen thin section ofhuman placenta was analysed by immunohistochemistry using a primaryantibody recognising von Willibrand Factor (positive control), andvisualised using an anti-rabbit secondary antibody coupled with alkalinephosphatase. The arrows show high levels of expression of vWF restrictedto the vascular endothelial cells.

FIG. 24.

Immunostaining of frozen placental section. A frozen thin section ofhuman placenta was analysed by immunohistochemistry using MGO-5 (arabbit polyclonal antibody raised against peptide MR 165) as the primaryantibody, and visualised using anti-rabbit secondary antibody coupledwith alkaline phosphatase. The arrows show high levels of expression ofECSM4 restricted to the vascular endothelial cells. Note that thesurrounding tissue shows little staining. Comparison with FIGS. 22 and23 shows that the expression of ECSM4 colocalises with that of vWF, aknown marker for vascular endothelial cells.

FIG. 25.

Immunohistochemical analysis of HUVEC cells: von Willibrand Factor(vWF). HUVEC cells were immobilised and analysed byinununohistochemistry using an antibody recognising von WillibrandFactor (a marker for endothelial cells) as the primary antibody andvisualised using anti-rabbit antibody coupled with alkaline phosphatase.The arrows show expression of vWF in a subset of the HUVEC cells.

FIG. 26.

Immunohistochemical analysis of HUVEC cells using the antibody MGO-7.HUVEC cells were immobilised and analysed by immunohistochemistry usingMGO-7 antibody (a rabbit polyclonal antibody raised against peptides MR311 and MR 336) as the primary antibody and visualised using anti-rabbitantibody coupled with alkaline phosphatase. The arrows show expressionof ECSM4 in a subset of the HUVEC cells. Note that the staining islocalised primarily to the cell surface of the cells.

FIG. 27. Expression of magic roundabout in vivo.

(A) Expression of MR detected by in situ hybridisation in of a placentalarteriole (a) and venule (b) (left, light field and right, dark field).(c) Immunohistochemical staining of magic roundabout in a placentalarteriole. Left, von Willibrand factor control and right, magicroundabout. (B) Expression of MR in tumour endothelium. Ganglioglioma(a) ×20 and (b) ×50. Left, light field; right, dark field. Arrowshighlight a vessel running diagonally down the section with anerythirocyte within it. Endothelial cells are strongly positive for MRexpression. Papillary bladder carcinoma (c) ×20 and (d) ×50. Thevascular core of the papilla of the tumour is strongly positive,particularly the ‘flat’ endothelial cells indicated by arrows. A magicroundabout antisense in situ probe was generated using T3 polymerasefrom IMAGE EST clone 1912098 (GenBank acc. A1278949). The plasmid waslinearised with Eco RI prior to probe synthesis. In situ analysis wasthen performed as described in Poulsom et al (1998) Eur. J.Histochemistry 42:121-132.

EXAMPLE 1

In Silico Cloning of Novel Endothelial Specific Genes.

We describe the use of two independent strategies for differentialexpression analysis combined with experimental verification to identifygenes specifically or preferentially expressed in vascular endothelium.

The first strategy was based the EST cluster expression analysis in thehuman UniGene gene index (Schuler et al, 1997). Recurrent gapped BLASTsearches (Altschul et al, 1997) were performed at very high stringencyagainst expressed sequence tags (ESTs) grouped in two pools. These twopools comprised endothelial cell and non-endothelial cell librariesderived from dbEST (Boguski et al, 1995). The second strategy employed asecond datamining tool: SAGEmap xProfiler. XProfiler is a freelyavailable on-line tool, which is a part of the NCBI's Cancer GenomeAnatomy Project (CGAP) (Strausberg et al, 1997, Cole et al, 1995). Whilethese two approaches alone were producing a discouragingly high numberof false positives, when both strategies were combined, predictionsproved exceptionally reliable and two novel candidateendothelial-specific genes have been identified. Full-length cDNAs havebeen identified in sequence databases. Another gene (EST cluster)corresponds to a partial cDNA sequence from a large-scale cDNAsequencing project and contains a region of similarity to theintracellular domain of human roundabout homologue 1 (ROBO1).

UniGene/EST Gene Index Screen

A pool of endothelial and a pool of non-endothelial sequences wereextracted using Sequence Retrieval System (SRS) version 5 from dbEST.The endothelial pool consisted of 11,117 ESTs from nine humanendothelial libraries (Table 1). The non-endothelial pool included173,137 ESTs from 108 human cell lines and microdissected tumourlibraries (Table 2). ESTs were extracted from dbEST release April 2000.Multiple FASTA files were transformed into a BLAST searchable databaseusing the pressdb programme. Table 3 shows the expression status of fiveknown endothelial cell-specific genes in these two pools.

Subsequently, the longest, representative sequence in each UniGenecluster (UniGene Build #111 May 2000, multiple FASTA file hs.seq.uniq)was searched using very high stringency BLAST against these two pools.If such representative sequence reported no hits, the rest of thesequences belonging to the cluster (UniGene multiple-FASTA file hs.seq)were used as BLAST queries. Finally, clusters with no hits in thenon-endothelial pool and at least one hit in the endothelial pool wereselected.

Optimising the BLAST E-value was crucial for the success of BLASTidentity-level searches. Too high an E-value would result in genepatalogues being reported. On the other hand, too low (stringent) anE-parameter would result in many false negatives, i.e. true positiveswould not be reported due to sequencing errors in EST data: ESTs arelarge-scale low-cost single pass sequences and have high error rate(Aaronson et al, 1996). In this work an E-value of 10e-20 was used insearches against non-endothelial EST pool and a more stringent 10e-30value in searches against the smaller endothelial pool. These valueswere deemed optimal after a series of test BLAST searches.

SAGE Data and SAGEmap xProfiler Differential Analysis

Web-based SAGE library subtraction (available at the National Center forBiotechnology Information SAGEmap xProfiler internet site) was utilisedas the second datamining strategy for the identification of novelendothelial specific or preferentially endothelial genes. Twoendothelial SAGE libraries (SAGE_Duke_HMVEC and SAGE_Duke_HMVEC+VEGFwith a total of 110,790 sequences) were compared to twenty-fournon-endothelial, cell line libraries (full list in Table 4, total of733,461 sequences). Table 5 shows the status of expression of five knownendothelial specific genes: von Willebrand's factor (vWF), two vascularendothelial growth factor receptors: fmns-like tyrosine kinase 1 (flt1)and kinase insert domain receptor (KDR), tyrosine kinase receptor typetie (TIE1) and tyrosine kinase receptor type tek (TIE2/TEK), in thesetwo SAGE pools.

Combined Data Gives Highly Accurate Predictions

Twenty known genes were selected in the UniGene/EST screen (Table 6).These genes had no hits in the non-endothelial pool and at least one hitin the endothelial pool. The list contained at least four endothelialspecific genes: TIE1, TIE2/TEK, LYVE1 and multimerin, indicating ˜20%accuracy of prediction. Other genes on the list, while certainlypreferentially expressed in the endothelial cells, might not beendothelial specific. To improve on the prediction accuracy we decidedto combine UniGene/EST screen with the xProfiler SAGE analysis. ThexProfiler output consisted of a list of genes with a ten times highernumber of tags in the endothelial than in the non-endothelial poolsorted according to the certainty of prediction. A 90% certaintythreshold was applied to this list. Table 7 shows how data from the twoapproaches were combined. Identity-level BLAST searches were performedon mRNAs (known genes) or phrap computed contigs (EST clustersrepresenting novel genes) to investigate how these genes wererepresented in the endothelial and non-endothelial pool. Subsequentexperimental verification by RT-PCR (FIG. 1) proved that the combinedapproach was 100% accurate, i.e. genes on the xProfiler list which hadno matches the non-endothelial EST pool and at least one match in theendothelial pool were indeed endothelial specific.

Discussion

There have been several reports of computer analysis of tissuetranscriptosomes. Usually an expression profile is constructed, based onthe number of tags assigned to a given gene or a class of genes(Bernstein et al, 1996, Welle et al, 1999, Bortoluzzi et al, 2000). Anattempt can be made to identify tissue-specific transcripts, for exampleVasmatzis et al, (1997) described three novel genes expressedexclusively in the prostate by in silico subtraction of libraries fromthe dbEST collection. Purpose made cDNA libraries may also be employed.Ten candidate granulocyte-specific genes have been identified byextensive sequence analysis of cDNA libraries derived from granulocytesand eleven other tissue samples, namely a hepatocyte cell line, foetalliver, infant liver, adult liver, subcutaneous fat, visceral fat, lung,colonic mucosa, keratinocytes, cornea and retina (Itoh et al, 1998).

An analysis similar to the dbEST-based approach taken by Vasmatzis etal, is complicated by the fact that endothelial cells are present in alltissues of the body and endothelial-ESTs are contaminating all bulktissue libraries. To validate this we used three well-known endothelialspecific genes: KDR, FLT1, and TIE-2 as queries for BLAST searchesagainst dbEST. Transcripts were present in a wide range of tissues withmultiple hits in well vascularised tissues (e.g. placenta, retina),embryonic (liver, spleen) or infant (brain) tissues. Additionally, wefound that simple subtraction of endothelial EST libraries against allother dbEST libraries failed to identify any specific genes (data notshown).

Two very different types of expression data resources were used in ourdatamining efforts. The UniGene/EST screen was based on expressedsequence tag libraries from dbEST. There are 9 human endotheliallibraries in the current release of dbEST with a relatively small totalnumber of ESTs: ˜11,117. Some well-known endothelial specific genes arenot represented in this dataset (Table 3). This limitation raised ourconcerns that genes with low levels of expression would be overlooked inour analysis. Therefore, we utilised another type of computableexpression data: CGAP SAGE libraries.

SAGE tags are sometimes called small ESTs (usually 10-11 bp in length).Their major advantage is that they can be unambiguously located withinthe cDNA: they are immediately adjacent to the most 3′ NlaIIIrestriction site. Though, there are only two endothelial CGAP SAGElibraries available at the moment, they contain an impressive total of˜1 11,000 tags—an approximately 10 times bigger dataset than the ˜11,117sequences in the endothelial EST pool. The combined approach proved veryaccurate (Table 8, FIG. 1) when verified by RT-PCR.

We report here identification of two novel highly endothelial specificgenes: endothelial cell-specific molecule 1 (ECSM1—UniGene entryHs.13957) and magic roundabout (UniGene entry Hs. 111518). For acomprehensive summary of data available on these genes see Table 8.

Our combined datamining approach together with experimental verificationis a powerful functional genomics tool. This type of analysis can beapplied to many cell types not just endothelial cells. The challenge ofidentifying the function of discovered genes remains, but bioinformaticstools such as structural genomics, or homology and motif searches canoffer insights that can then be verified experimentally.

In summary, this screening approach has allowed the identification ofnovel endothelial cell specific genes and known genes whose expressionwas not known to be specific to endothelial cells. This identificationboth advances our understanding of endothelial cell biology and providesnew pharmaceutical targets for imaging, diagnosing and treating medicalconditions involving the endothelium.

Methods

PERL Scripts

A number of PERL scripts were generated to facilitate large scalesequence retrieval, BLAST search submissions, and automatic BLAST outputanalysis.

Database Sequence Retrieval

Locally stored UniGene files (Build #111, release date May 2000) wereused in the preparation of this report. The UniGene website can beaccessed on the National Center for Biotechnology Information internetsite, and UniGene files can be downloaded from the ftp repository:ftp://ncbi.nlm.nih.gov/repository/unigene/. Representative sequences forthe human subset of UniGene (the longest EST within the cluster) arestored in the file Hs.seq.uniq, while all ESTs belonging to the clusterare stored in a separate file called Hs.seq.

Sequences were extracted from the dbEST database accessed locally at theHGMP centre using the Sequence Retrieval System (SRS version 5) getzcommand. This was done repeatedly using a PERL script for all thelibraries in the endothelial and non-endothelial subsets, and sequenceswere merged into two multiple-FASTA files.

Selection Criteria for Non-Endothelial EST Libraries

Selection of 108 non-endothelial dbEST libraries was largely manual.Initially the list of all available dbEST libraries, which is availableat the National Center for Biotechnology Information internet site wassearched using the keyword ‘cells’ and the phrase ‘cell line’. Whilethis searched identified most of the libraries, additional keywords hadto be added for the list to be full: ‘melanocyte’, ‘macrophage’, ‘HeLa’,‘fibroblast’. In some cases, detailed library description was consultedto confirm that library is derived from a cell line/primary culture. Wealso added a number of CGAP microdissected tumour libraries. For that,Library Browser (available at the National Center for BiotechnologyInformation internet site, was used to search for the keyword‘microdissected’.

UniGene Gene Index Screen

The UniGene gene transcript index was screened against the EST divisionof GenBank, dbEST. Both UniGene and dbEST were developed at the NationalCentre for Biotechnology Information (NCBI). UniGene is a collection ofEST clusters corresponding to putative unique genes. It currentlyconsists of four datasets: human, mouse, rat and zebrafish. The humandataset is comprised of approximately 90,000 clusters (UniGene Build#111 May 2000). By means of very high stringency BLAST identitysearches, we aimed to identify those UniGene genes that have transcriptsin the endothelial and not in the non-endothelial cell-type dbESTlibraries. Thrpughout the project, University of Washington blast2 whichis a gapped version was used as BLAST implementation. The E-value wasset to 10e-20 in searches against the non-endothelial EST pool and to10e-30 in searches against the smaller endothelial pool.

While UniGene does not provide consensus sequences for its clusters, thelongest sequence within the cluster is identified Thus, this longestrepresentative sequence (multiple FASTA file Hs.seq.uniq) was searchedusing very high stringency BLAST against the endothelial andnon-endothelial EST pool. If such representative sequence reported nomatches, the rest of the sequences belonging to the cluster (UniGenemultiple-FASTA file Hs.seq) followed as BLAST queries. Finally, clusterswith no matches in the non-endothelial pool and at least one match inthe endothelial pool were selected using PERL scripts analysing BLASTtextual output.

xProfiler SAGE Subtraction

xProfiler enables an on-line user to perform a differential comparisonof any combination of forty seven serial analysis of gene expression(SAGE) libraries with a total of ˜2,300,000 SAGE tags using a dedicatedstatistical algorithm (Chen et al, 1998). xProfiler can be accessed onthe National Center for Biotechnology Information internet site. SAGEitself is a quantitative expression technology in which genes areidentified by typically a 10 or 11 bp sequence tag adjacent to thecDNA's most 3′ NlaIII restriction site (Velculescu et al, 1995).

The two available endothelial cell libraries (SAGE_Duke_HMVEC andSAGE_Duke_HMVEC+VEGF) defined pool A and twenty-four (see Table 4 forlist) non-endothelial libraries together built pool B. The approach wasverified by establishing the status of expression of the five referenceendothelial specific genes in the two SAGE pools (Table 5) using Gene toTag Mapping, available on the National Center for BiotechnologyInformation internet site. Subsequently, xProfiler was used to selectgenes differentially expressed between the pools A and B. The xProfileroutput consisted of a list of genes with a ten fold difference in thenumber of tags in the endothelial compared to the non-endothelial poolsorted according to the certainty of prediction. A 90% certaintythreshold was applied to this list.

The other CGAP's on-line differential expression analysis tool, DigitalDifferential Display (DDD), relies on EST expression data (sourcelibrary info) instead of using SAGE tags. We attempted to utilise thistool similarly to SAGEmap xProfiler but have been unable to obtainuseful results. Five out of nine endothelial and sixty-four out ofhundred and eight non-endothelial cell libraries used in ourBLAST-oriented approach were available for on-line analysis using DDD,available at the National Center for Biotechnology Information internetsite. When such analysis was performed the following were fifteen topscoring genes: annexin A2, actin gamma 1, nbosomal protein large P0,plasminogen activator inhibitor type I, thymosin beta 4, peptidyloprolylisomerase A, ribosomal protein L13a, laminin receptor 1 (ribosomalprotein SA), eukaryotic translation elongation factor 1 alpha 1,vimentin, ferritin heavy polypeptide, ribosomal protein L3, ribosomalprotein S18, ribosomal protein L19, tumour proteintranslationally-controlled 1. This list was rather surprising, did notinclude any well-known endothelial specific genes, did not have anyoverlap with SAGE results (Table 8), and contained many genes, that inthe literature are reported to be ubiquitously expressed (ribosomalproteins, actin, vimentin, ferritin). A major advantage of ourUniGene/EST screen is that instead of relying on source library data andfallible EST clustering algorithms it actually performs identity-levelBLAST comparisons in search of transcripts corresponding to a gene.

Mining Data on UniGene Clusters

To quickly access information about UniGene entries (e.g. literaturereferences, STS sites, homologues, references to function) on-lineresources were routinely used: NCBI's UniGene and LocusLink interfacesand Online Mendelian Inheritance in Man.

ESTs in UniGene clusters are not assembled into contigs, so before anysequence analysis, contigs were created using phrap assembler (fordocumentation on phrap see the bozeman.mbt internet site).

To analyse genomic contig AC005795 (44,399) bp containing ECSM1, NIXInternet interface for multi-application analysis of large unknownnucleotide sequences was used. For further information on NIX see thehgmp.mrc internet site. Alignment of ECSM1 against AC005795 was obtainedusing the NCBI interface to the Human Genome Interface: the NCBI MapViewer. For further information on the NCBI Map Viewer see the NationalCenter for Biotechnology Information internet site.

To search for possible transmembrane domains and signal sequences intranslated nucleotide sequences three Internet based applications wereused: DAS (Cserzo et al, 1997), TopPred2 (Heijne 1992), and SignalP(Nielsen et al, 1997).

PERL Scripts

A number of PERL scripts were generated to facilitate large scalesequence retrieval, BLAST search submissions, and automatic BLAST outputanalysis.

Experimental Verification

To experimentally verify specificity of expression we used the reversetranscription polymerase chain reaction (RT-PCR). RNA was extracted fromthree endothelial and seven non-endothelial cell types cultured invitro. Endothelial cultures were as follows: HMVEC (human microvascularendothelial cells), HUVEC (human umbilical vein endothelial cells)confluent culture and HUVEC proliferating culture. Non-endothelialcultures were as follows: normal endometrial stromal (NES) cells grownin normoxia and NES grown in hypoxia, MDA 453 and MDA 468 breastcarcinoma cell lines, HeLa, FEK4 fibroblasts cultured in normoxia andFEK4 fibroblasts cultured in hypoxia, and SW480, HCT116—two colorectalepithelium cell lines.

If a sequence tagged site (STS) was available, dbSTS PCR primers wereused and cycle conditions suggested in the dbSTS entry followed.Otherwise, primers were designed using the Primer3 programme. Primersare listed in Table 9.

Tissue Culture Media, RNA Extraction and cDNA Synthesis

Cell-lines were cultured in vitro according to standard tissue cultureprotocols. In particular, endothelial media were supplemented with ECGS(endothelial cell growth supplement—Sigma), and heparin (Sigma) topromote growth. Total RNA was extracted using the RNeasy Minikit(Qiagen) and cDNA synthesised using the Reverse-IT 1^(st) StrandSynthesis Kit (ABgene).

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TABLE 1 Nine human endothelial libraries from dbEST Human aorticendothelium, 20 sequences, in vitro culture Human endothelial cells, 346sequences, primary isolate Human endothelial cell (Y. Mitsui), 3sequences, in vitro culture Stratagene endothelial cell 937223, 7171sequences, primary isolate Aorta endothelial cells, 1245 sequences,primary isolate Aorta endothelial cells, TNF treated, 1908 sequences,primary isolate Umbilical vein endothelial cells I, 9 sequences HDMECcDNA library, 11 sequences, in vitro culture Umbilical vein endothelialcells II, 404 sequences

TABLE 2 Non-endothelial dbEST libraries.  1. Activated T-cells I  2.Activated T-cells II  3. Activated T-cells III  4. Activated T-cells IV 5. Activated T-cells IX  6. Activated T-cells V  7. Activated T-cellsVI  8. Activated T-cells VII  9. Activated T-cells VIII  10. ActivatedT-cells X  11. Activated T-cells XI  12. Activated T-cells XII  13.Activated T-cells XX  14. CAMA1Ee cell line I  15. CAMA1Ee cell line II 16. CCRF-CEM cells, cyclohexamide treated I  17. CdnA library ofactivated B cell line 3D5  18. Chromosome 7 HeLa cDNA Library  19. Coloncarcinoma (Caco-2) cell line I  20. Colon carcinoma (Caco-2) cell lineII  21. Colon carcinoma (HCC) cell line  22. Colon carcinoma (HCC) cellline II  23. HCC cell line (matastasis to liver in mouse)  24. HCC cellline (matastasis to liver in mouse) II  25. HeLa cDNA (T. Noma)  26.HeLa SRIG (Synthetic retinoids induced genes)  27. Homo sapiensmonocyte-derived macrophages  28. HSC172 cells I  29. HSC172 cells II 30. Human 23132 gastric carcinoma cell line  31. Human breast cancercell line Bcap 37  32. Human cell line A431 subclone  33. Human cellline AGZY-83a  34. Human cell line PCI-O6A  35. Human cell line PCI-O6B 36. Human cell line SK-N-MC  37. Human cell line TF-1 (D. L. Ma)  38.Human exocervical cells (C G Lee)  39. Human fibrosarcoma cell lineHT1080  40. Human fibrosarcoma cell line HT1080-6TGc5  41. Human gastriccancer SGC-7901 cell line  42. Human GM-CSF-deprived TF-1 cell line(Liu, Hongtao)  43. Human HeLa (Y. Wang)  44. Human HeLa cells (M.Lovett)  45. Human Jurkat cell line mRNA (Thiele, K.)  46. Human K562erythroleukemic cells  47. Human lung cancer cell line A549.A549  48.Human nasopharyngeal carcinoma cell line HNE1  49. Human neuroblastomaSK-ER3 cells (M. Garnier)  50. Human newborn melanocytes (T. Vogt)  51.Human pancreatic cancer cell line Patu 8988t  52. Human primarymelanocytes mRNA (I. M. Eisenbarth)  53. Human promyelocytic HL60 cellline (S. Herblot)  54. Human retina cell line ARPE-19  55. Humansalivary gland cell line HSG  56. Human White blood cells  57. JurkatT-cells I  58. Jurkat T-cells II  59. Jurkat T-cells III  60. JurkatT-cells V  61. Jurkat T-cells VI  62. Liver HepG2 cell line.  63. LNCAPcells I  64. Macrophage I  65. Macrophage II  66. Macrophage, subtracted(total CdNA)  67. MCF7 cell line  68. Namalwa B cells I  69. Namalwa Bcells II  70. NCI_CGAP_Br4  71. NCI_CGAP_Br5  72. NCI_CGAP_CLL1  73.NCI_CGAP_GCB0  74. NCI_CGAP_GCB1  75. NCI_CGAP_HN1  76. NCI_CGAP_HN3 77. NCI_CGAP_HN4  78. NCI_CGAP_HSC1  79. NCI_CGAP_Li1  80. NCI_CGAP_Li2 81. NCI_CGAP_Ov5  82. NCI_CGAP_Ov6  83. NCI_CGAP_Pr1  84. NCI_CGAP_Pr10 85. NCI_CGAP_Pr11  86. NCI_CGAP_Pr16  87. NCI_CGAP_Pr18  88.NCI_CGAP_Pr2  89. NCI_CGAP_Pr20  90. NCI_CGAP_Pr24  91. NCI_CGAP_Pr25 92. NCI_CGAP_Pr3  93. NCI_CGAP_Pr4  94. NCI_CGAP_Pr4.1  95.NCI_CGAP_Pr5  96. NCI_CGAP_Pr6  97. NCI_CGAP_Pr7  98. NCI_CGAP_Pr8  99.NCI_CGAP_Pr9 100. Normal Human Trabecular Bone Cells 101. Raji cells,cyclohexamide treated I 102. Retinal pigment epithelium 0041 cell line103. Retinoid treated HeLa cells 104. Soares melanocyte 2NbHM 105.Soares_senescent_fibroblasts_Nb HSF 106. Stratagene HeLa cell s3 937216107. Supt cells 108. T, Human adult Rhabdomyosarcoma cell-line

TABLE 3 Five genes known to be endothelial specific genes in the dbESTpools. The number of ESTs in the endothelial pool is relatively small(~11,117) and not all known endothelial genes are represented Hits inthe non- Hits in the Known endothelial specific gene endothelial poolendothelial pool von Willebrand factor (vWF) 1 27 flt1 VEGF receptor — —KDR VEGF receptor 1 — TIE1 tyrosine kinase —  5 TIE2/TEK tyrosine kinase—  2

TABLE 4 Twenty-four non-endothelial cell SAGE-CGAP libraries. SYMBOLDESCRIPTION SAGE_HCT116 Colon, cell line derived from colorectalcarcinoma SAGE_Caco_2 Colon, colorectal carcinoma cell lineSAGE_Duke_H392 Brain, Duke glioblastoma multiforme cell line SAGE_SW837Colon, cancer cell line SAGE_RKO Colon, cancer cell line SAGE_NHA(5th)Brain, normal human astrocyte cells harvested at passage 5 SAGE_ES2-1Ovarian Clear cell carcinoma cell line ES-2, poorly differentiatedSAGE_OVCA432-2 Ovary, carcinoma cell line OVCA432 SAGE_OV1063-3 Ovary,carcinoma cell line OV1063 SAGE_Duke_mhh-1 Brain, c-myc negativemedulloblastoma cell line mhh-1 SAGE_Duke_H341 Brain, c-myc positivemedulloblastoma cell line H341 SAGE_HOSE_4 Ovary, normal surfaceepithelium SAGE_OVP-5 Ovary, pooled cancer cell lines SAGE_LNCaPProstate, cell line. Androgen dependent SAGE_HMEC-B41 Cell cultureHMEC-B41 of normal human mammary epithelial cells SAGE_MDA453 Cell lineMDA-MB-453 of human breast carcinoma SAGE_SKBR3 ATCC cell line SK-BR-3.Human breast adenocarcinoma SAGE_A2780-9 Ovary, ovarian cancer cell lineA2780 SAGE_Duke_(—) Brain, glioblastoma multiforme cell line, H247H247_normal SAGE_Duke_(—) Brain, Duke glioblastoma multiforme cell line,H247_Hypoxia H247, grown under 1.5% oxygen SAGE_Duke_(—) Skin,post-crisis survival fibroblast cell-line post_crisis_(—) fibroblastsSAGE_Duke_(—) Skin, large T antigen transformed human precrisis_(—)fibroblasts clones fibroblasts SAGE_A Prostate, cancer cell line.Induced with synthetic androgen SAGE_IOSE29-11 Ovary, surface epitheliumline

TABLE 5 Five known endothelial specific genes in the CGAP SAGE pools.TIE1 and TIE2/TEK have multiple hits in the non-endothelial pool (mostin normal or carcinoma cell lines of ovarian origin). vWF is mostendothelial specific having 80 hits in the endothelial pool and only onehit in the non-endothelial pool. Tags in the Known endothelial Tags inthe non-endothelial endothelial sage specific gene sage librarieslibraries von Willebrand factor 1 (colon carcinoma cell line) 80 (VWF)flt1 VEGF receptor — — KDR VEGF receptor 1 (IOSE29 ovarian surface  6epithelium cell line) TIE1 tyrosine kinase 17 (ovarian tumour and 27normal ovarian epithelium cell lines) TIE2/TEK tyrosine 4 (ovariancarcinoma and  2 kinase glioblastoma multiforme cell lines)

TABLE 6 Results of the UniGene/EST screen. Twenty known genes wereselected in the UniGene/EST screen (no hits in the non-endothelial pooland minimum one hit in the endothelial pool). At least four of thesegenes are known endothelial specific genes: TIE1, TIE2/TEK, LYVE1 andmultimerin, indicating ~20% prediction accuracy. Other genes, whilecertainly preferentially expressed in the endothelial cells, may not beendothelial specific. UniGene Endothelial Description ID hits TIE1receptor endothelial tyrosine kinase Hs.78824 5 Cytosolic phospholipaseA2; involved in the Hs.211587 3 metabolism of eicosanoids Branched chainalpha-ketoacid dehydrogenase Hs.1265 2 CGMP-dependent protein kinase;cloned from Hs.2689 2 aorta cDNA, strongly expressed in wellvascularised tissues like aorta, heart, and uterus (Tamura et al, 1996)Lymphatic vessel endothelial hyaluronan Hs.17917 2 receptor 1 -LYVE1(Banerji et al, 1999) TRAF interacting protein: TNF signalling Hs.212542 pathway Multimerin: a very big endothelial specific Hs.32934 2protein; binds platelet factor V, can also be found in platelets(Hayward et al, 1996) Diubiquitin (a member of the ubiquitin family);Hs.44532 2 reported in dendrytic and B lymphocyte cells; involved inantigen processing; this is first evidence that it is also present inendothelial cells (Bates et al, 1997) Beta-transducin family protein;also a homolog Hs.85570 2 of D. melanogaster gene notchless: a novelWD40 repeat containing protein that modulates Notch signalling activityTIE2/TEK receptor endothelial tyrosine kinase Hs.89640 2 BCL2 associatedX protein (BAX) Hs.159428 2 Sepiapterin reductase mRNA Hs.160100 2Retinoic acid receptor beta (RARB) Hs.171495 2 ST2 receptor: a homologof the interleukin 1 Hs.66 1 receptor Mitogen activated protein kinase 8(MAPK8) Hs.859 1 ERG gene related to the ETS oncogene Hs.45514 1 PP35similar to E. coli yhdg and R. Capsulatus Hs.97627 1 nifR3Interphotoreceptor matrix proteoglycan; Hs.129882 1 strongly expressedin retina and umbilical cord vein (Felbor et al, 1998) Methylmalonatesemialdehyde dehydrogenase Hs.170008 1 gene, HTLV-I related endogenousretroviral sequence Hs.247963 1

TABLE 7 xProfiler differential analysis was combined with data from theUniGene/EST screen achieving 100% certainty of prediction. xProfiler'soutput lists genes with 10-times higher number of tags in theendothelial than in the non-endothelial pool of SAGE-CGAP libraries.Hits corresponding to these genes in the endothelial and non-endothelialEST pools were identified by identity-level BLAST searches for mRNA(known genes) or phrap computed contig sequences (EST clustersrepresenting novel genes). Genes are sorted according to the number ofhits in the non-endothelial EST pool. Known and predicted novelendothelial specific genes are in bold. Hits in X profiler Hits in non-Unigene prediction endothelial endothelial ID Gene description certaintyEST pool EST pool Hs.13957 ESTs-ECSM1 97% 4 0 Hs.111518 magicroundabout, 100% 4 0 distant homology to human roundabout 1 Hs.268107multimerin 92% 5 0 Hs.155106 calcitonin receptor- 97% 0 0 like receptoractivity modifying protein 2 Hs.233955 ESTs 96% 0 0 Hs.26530 serumdeprivation 94% 3 1 response (phosphatidylserine- binding protein)Hs.83213 fatty acid binding 100% 3 1 protein 4 Hs.110802 von Willebrand100% 25 1 factor Hs.76206 cadherin 5, VE- 100% 4 1 cadherin (vascularendothelium) Hs.2271 endothelin 1 98% 9 2 Hs.119129 collagen, type IV,100% 4 6 alpha 1 Hs.78146 platelet/endothelial 99% 18 5 cell adhesionmolecule (CD31 antigen) Hs.76224 EGF-containing 100% 37 9 fibulin-likeextracellular matrix protein 1 Hs.75511 connective tissue 100% 34 48growth factor

TABLE 8 Summary of available information on magic roundabout. UniGeneTransmembrane Mapping information cluster ID Longest segments, Genomiccontext and size Full-length cDNA ORF signal peptide Genomic clonesDescription ECSM1 Hs.13957 103 aa Genomic neighbour: Tropomyosin 1100 bpconfirmed dbSTS G26129 and G28043 with 5′RACE Chr. 19 Gene Map 98:Marker SGC33470, Marker stSG3414, IntervalD19S425-D19S418 AC005945,AC005795 (partial identity) Magic HS. 111518 Partial cDNA 417 aa Onetransmembrane Genomic neighbour: integral 468 aa region of homology toroundabout FLJ20798 fis, domain predicted by transmembrane protein 1(ITM1) the cytoplasmic portion of the clone TopPred2 and DAS. |roundabout axon guidance 2076 bp ADSU02031 protein family: human ROBO1,(acc.AK000805) No signal peptide dbSTS G14646 and G14937 rat ROBO1 andmouse dutt1 detected in the (E = 1.3e-09) 1496 bp available 417 as ORFChr. 11. Gene Map 98: Marker (SignalP)however the SHGC-11739, IntervalORF has no apparent up-stream true protein product is D11S1353-D11S93limit. This and size comparison very likely to be larger to ROBO1(1651aa) suggests that true protein is very likely to be much larger Possiblealternative polyA sites: the cDNA clone from adipocyte tissue seems tobe polyadenylated in a different position to the sequence from theUniGene contig

TABLE 9 List of primers used in RT-PCR reactions. dbSTS primers wereused if a UniGene entry contained a sequence tagged site (STS).Otherwise, primers were designed using the Primer3 programme. Primers(sequence or GenBank Gene Accession for the STS) ECSM1-Hs.13957 G26129Magic roundabout-Hs.111518 G14937 calcitonin receptor-like receptorG26129 activity modifying 2 Hs.233955 G21261 fatty acid binding protein4 5′-TGC AGC TTC CTT CTC ACC TT-3′ (SEQ ID NO:15) 5′-TCA CAT CCC CAT TCACAC TG-3′ (SEQ ID NO:16) von Willebrand factor 5′-TGT ACC ATG AGG TTCTCA ATG C-3′ (SEQ ID NO:17) 5′-TTA TTG TGG GCT CAG AAG GG-3′ (SEQ IDNO:18) serum deprivation response protein G21528 collagen, type IV,alpha 1 G07125 EGF-containing fibulin-like G06992 extracellular matrixprotein 1 connective tissue growth factor 5′-CAA ATG CTT CCA GGT GAAAAA-3′ (SEQ ID NO:19) 5′-CGT TCA AAG CAT GAA ATG GA-3′ (SEQ ID NO:20)

TABLE 10 ESTs belonging to ECSM1 contig sequence are as follows: ESTSEQUENCES(30) AI540508, cDNAcloneIMAGE: 2209821, Uterus, 3′read, 2.1 kbAI870175, cDNAcloneIMAGE: 2424998, Uterus, 3′read, 1.7 kb AI978643,cDNAcloneIMAGE: 2491824, Uterus, 3′read, 1.3 kb AI473856,cDNAcloneIMAGE: 2044374, Lymph, 3′read AI037900, cDNAcloneIMAGE:1657707, Wholeembryo, 3′read, 1.2 kb AI417620, cDNAcloneIMAGE: 2115082,3′read, 1.0 kb AA147817, cDNAcloneIMAGE: 590062, 3′read AA968592,cDNAcloneIMAGE: 1578323, 3′read, 0.7 kb AW474729, cDNAcloneIMAGE:2853635, Uterus, 3′read R02352, cDNAcloneIMAGE: 124282, 3′read, 0.7 kbR01889, cDNAcloneIMAGE: 124485, 5′read, 0.7 kb AA446606, cDNAcloneIMAGE:783693, Wholeembryo, 3′read R02456, cDNAcloneIMAGE: 124282, 5′read, 0.7kb T72705, cDNAcloneIMAGE: 108686, 5′read, 0.7 kb R01890,cDNAcloneIMAGE: 124485, 3′read, 0.7 kb AA147925, cDNAcloneIMAGE: 590014,5′read AI131471, cDNAcloneIMAGE: 1709098, Heart, 3′read, 0.6 kbAA733177, cDNAclone399421, Heart, 3′read AI039489, cDNAcloneIMAGE:1658903, Wholeembryo, 3′read, 0.6 kb AI128585, cDNAcloneIMAGE: 1691245,Heart, 3′read, 0.6 kb AI540506, cDNAcloneIMAGE: 2209817, Uterus, 3′read,0.6 kb AA894832, cDNAcloneIMAGE: 1502815, Kidney, 3′read, 0.5 kbAW057578, cDNAcloneIMAGE: 2553014, Pooled, 3′read, 0.3 kb AA729975,cDNAcloneIMAGE: 1257976, GermCell, 0.3 kb AI131016, cDNAcloneIMAGE:1706622, Heart, 3′read, 0.2 kb AA147965, cDNAcloneIMAGE: 590062, 5′readAA446735, cDNAcloneIMAGE: 783693, Wholeembryo, 5′read AA147867,cDNAcloneIMAGE: 590014, 3′read AI497866, cDNAcloneIMAGE: 2125892,Pooled, 3′read T72636, cDNAcloneIMAGE: 108686, 3′read, 0.7 kb

TABLE 11 ESTs within the magic roundabout sequence: EST sequences inmagic roundabout (55): AI803963, cDNAcloneIMAGE: 2069520, 3′read, 0.9 kbW88669, cDNAcloneIMAGE: 417844, 3′read, 0.7 kb AI184863, cDNAcloneIMAGE:1565500, Pooled, 3′read, 0.6 kb AA011319, cDNAcloneIMAGE: 359779, Heart,3′read, 0.6 kb AA302765, cDNAcloneATCC: 194652, Adipose, 3′readAI278949, cDNAcloneIMAGE: 1912098, Colon, 3′read, 0.7 kb AI265775,cDNAcloneIMAGE: 2006542, Ovary, 3′read AA746200, cDNAcloneIMAGE:1324396, Kidney, 0.5 kb N78762, cDNAcloneIMAGE: 301290, Lung, 3′readAI352263, cDNAcloneIMAGE: 1940638, Wholeembryo, 3′read, 0.6 kb AA630260,cDNAcloneIMAGE: 854855, Lung, 3′read, 0.5 kb C20950, cDNAclone(no-name),3′read W88875, cDNAcloneIMAGE: 417844, 5′read, 0.7 kb AA156022,cDNAcloneIMAGE: 590120, 3′read N93972, cDNAcloneIMAGE: 309369, Lung,3′read, 1.7 kb AI217602, cDNAcloneIMAGE: 1732380, Heart, 3′read, 0.5 kbAW294276, cDNAcloneIMAGE: 2726′347, 3′read AA010931, cDNAcloneIMAGE:359779, Heart, 5′read, 0.6 kb AA303624, cDNAcloneATCC: 115215, Aorta,5′read AI366745, cDNAcloneIMAGE: 1935056, 3′read, 0.5 kb AA327257,cDNAcloneATCC: 127927, Colon, 5′read C06489, cDNAclonehbc5849, PancreasBE218677, cDNAcloneIMAGE: 3176164; lung, 3′read AA335675, cDNAcloneATCC:137498, Testis, 5′read R84975, cDNAcloneIMAGE: 180552, Brain, 3′read,2.1 kb AI926445, cDNAcloneIMAGE: 2459442, Stomach, 3′read, 1.9 kbH61208, cDNAcloneIMAGE: 236318, Ovary, 3′read, 1.9 kb AA335358,cDNAcloneATCC: 137019, Testis, 5′read AI129190, cDNAcloneIMAGE: 1509564,Pooled, 3′read, 0.8 kb T59188, cDNAcloneIMAGE: 74634, Spleen, 5′read,0.8 kb T59150, cDNAcloneIMAGE: 74634, Spleen, 3′read, 0.8 kb R53174,cDNAcloneIMAGE: 154350, Breast, 5′read, 0.8 kb AA156150, cDNAcloneIMAGE:590120, 5′read AA302509, cDNAcloneATCC: 114727, Aorta, 5′read R99429,cDNAcloneIMAGE: 201985, 5′read, 2.4 kb AI813787, cDNAcloneIMAGE:2421627, Pancreas, 3′read, 1.2 kb H62113, cDNAcloneIMAGE: 236316, Ovary,5′read, 1.0 kb R16422, cDNAcloneIMAGE: 129313, 5′read, 0.7 kb T48993,cDNActoneIMAGE: 70531, Placenta, 5′read, 0.6 kb T05694,cDNAcloneHFBDF13, Brain R84531, cDNAcloneIMAGE: 180104, Brain, 5′read,2.2 kb AI903080, cDNAclone(no-name), breast AI903083,cDNAclone(no-name), breast AA302764, cDNAcloneATCC: 194652, Adipose,5′read AA341407, cDNAcloneATCC: 143064, Kidney, 5′read W16503,cDNAcloneIMAGE: 301194, Lung, 5′read AW801246, cDNAclone(no-name),uterus AW959183, cDNAclone(no-name) R85924, cDNAcloneIMAGE: 180104,Brain, 3′read, 2.2 kb AA358843, cDNAcloneATCC: 162953, Lung, 5′readBE161769, cDNAclone(no-name), head-neck W40341, cDNAcloneIMAGE: 309369,Lung, 5′read, 1.7 kb AA876225, cDNAcloneIMAGE: 1257188, GermCell, 3′readR99441, cDNAcloneIMAGE: 202009, 5′read, 2.3 kb W76132, cDNAcloneIMAGE:344982, Heart, 5′read, 1.4 kb,

TABLE 12 110 ESTs in the mouse magic roundabout cluster (Mm. 27782)AI427548, cDNAcloneIMAGE: 521115, Muscle, 3′read AV022394,cDNAclone1190026N09, 3′read BB219221, cDNAcloneA530053H04, 3′readAI604803, cDNAcloneIMAGE: 388336, Embryo, 3′read AI504730,cDNAcloneIMAGE: 964027, Mammarygland, 3′read AI430395, cDNAcloneIMAGE:388336, Embryo, 5′read AI181963, cDNAcloneIMAGE: 1451626, Liver, 3′readAV020471, cDNAclone1190017N14, 3′read BB219225, cDNAcloneA530053H12,3′read BB224304, cDNAcloneA530086A21, 3′read BB527740,cDNAcloneD930042M18, 3′read W66614, cDNAcloneIMAGE: 388336, Embryo,5′read BB097630, cDNAclone9430060E21, 3′read AI152731, cDNAcloneIMAGE:1478154, Uterus, 5′read AW742708, cDNAcloneIMAGE: 2780289, innerear,170pooled, 3′read BB118169, cDNAclone9530064M17, 3′read AI839154,cDNAcloneUI-M-AO0-ach-e-11-0-UI, 3′read BB206388, cDNAcloneA430075J10,3′read BB381670, cDNAcloneC230015E01, 3′read BB199721,cDNAcloneA430017A19, 3′read AI593217, cDNAcloneIMAGE: 1177959,Mammarygland, 3′read BB219411, cDNAcloneA530054L01, 3′read BB220744,cDNAcloneA530061M19, 3′read BB220944, cDNAcloneA530062O22, 3′readBB390078, cDNAcloneC230066L23, 3′read BB220730, cDNAcloneA530061L13,3′read AI615527, cDNAcloneIMAGE: 964027, Mammarygland, 5′read AI882477,cDNAcloneIMAGE: 1396822, Mammarygland, 5′read AV025281,cDNAclone1200012D01, 3′read BB470462, cDNAcloneD230033L23, 3′readBB247620, cDNAcloneA730020G03, 3′read BB555377, cDNAcloneE330019B13,3′read BB512960, cDNAcloneD730043I21 BB400157, cDNAcloneC330017F17,3′read BB320465, cDNAcloneB230385O10, 3′read BB105670,cDNAclone9430096H10, 3′read BB441462, cDNAcloneD030027B11, 3′readBB137530, cDNAclone9830142O07, 3′read AA553155, cDNAcloneIMAGE: 964027,Mammarygland, 5′read BB319763, cDNAcloneB230382G07, 3′read BB451051,cDNAcloneD130007I05, 3′read BB504672, cDNAcloneD630049J11, 3′readAI429453, cDNAcloneIMAGE: 569122, Embryo, 3′read BB190585,cDNAcloneA330062J23, 3′read BB257082, cDNAcloneA730076M18, 3′readBB386699, cDNAcloneC230047P06, 3′read BB295814, cDNAcloneB130042A09,3′read BB450972, cDNAcloneD130007A22, 3′read AA718562, cDNAcloneIMAGE:1177959, Mammarygland, 5′read BB223775, cDNAcloneA530083K18, 3′readAV020555, cDNAclone1190018G05, 3′read BB226083, cDNAcloneA530095K11,3′read BB482105, cDNAcloneD430007O19, 3′read BB381671,cDNAcloneC230015E02, 3′read BB383758, cDNAcloneC230030C02, 3′readBB257519, cDNAcloneA730080D13, 3′read BB265667, cDNAcloneA830021I17,3′read BB254777, cDNAcloneA730063K20, 3′read AV240775,cDNAclone4732443F15, 3′read BB315010, cDNAcloneB230352H04, 3′readBB390074, cDNAcloneC230066L16, 3′read BB517605, cDNAcloneD830025B17,3′read BB484410, cDNAcloneD430025H01, 3′read BB357583,cDNAcloneC030022J01, 3′read AV225639, cDNAclone3830431D12, 3′readBB554921, cDNAcloneE330016A12, 3′read BB161650, cDNAcloneA130061H21,3′read BB106720, cDNAclone9530002M22, 3′read BB535465,cDNAcloneE030043P14, 3′read BB357738, cDNAcloneC030024B10, 3′readAV285588, cDNAclone5031411M12 BB188339, cDNAcloneA330048H22, 3′readAV337749, cDNAclone6430404F19, 3′read BB065281, cDNAclone8030443H10,3′read BB148059, cDNAclone9930104N19, 3′read AV252251,cDNAclone4833438P20, 3′read BB184506, cDNAcloneA330012J24, 3′readBB522445, cDNAcloneD930007M08, 3′read BB520366, cDNAcloneD830041K23,3′read AV127290, cDNAclone2700047J01, 3′read BB248651,cDNAcloneA730027F04, 3′read BB008452, cDNAclone4732482M24, 3′readBB550719, cDNAcloneE230024C07, 3′read BB182033, cDNAcloneA230095N14,3′read BB480258, cDNAcloneD330045D17, 3′read BB004855,cDNAclone4732463E03, 3′read AV379748, cDNAclone9230013A19, 3′readBB552137, cDNAcloneE230035B12, 3′read BB288263, cDNAcloneIMAGE: 3490042,mammary, 5′read BB215681, cDNAcloneA530026M11, 3′read BB251356,cDNAcloneA730046B16, 3′read BB503441, cDNAcloneD630043F10, 3′readBB500571, cDNAcloneD630029E03, 3′read BB199833, cDNAcloneA430017K13,3′read BB533549, cDNAcloneE030030K03, 3′read BB098399,cDNAclone9430063L18, 3′read BB213310, cDNAcloneA530009E09, 3′readBB240699, cDNAcloneA630083B14, 3′read BB217106, cDNAcloneA530040N24,3′read BB057432, cDNAclone7120459H22, 3′read BB214645,cDNAcloneA530021N22, 3′read BB218254, cDNAcloneA530048K12, 3′readBB319841, cDNAcloneB230382O06, 3′read BB459759, cDNAcloneD130063G22,3′read BB485618, cDNAcloneD430032M09, 3′read BB517699,cDNAcloneD830025J18, 3′read BB535595, cDNAcloneE030044M09, 3′readBB536291, cDNAcloneE030049D17, 3′read BB552689, cDNAcloneE330001A16,3′read BB552709, cDNAcloneE33C001C16, 3′read

EXAMPLE 2

ECSM4 Expression is Restricted to Endothelial Cells.

In situ hybridisation (ISH) of tumour and normal tissues showed that theexpression of ECSM4 is restricted to vascular endothelial cells in adultangiogenic vessels only. Analysis of normal tissues showed thatexpression of ECSM4 is detected in human placenta and umbilical cordfoetal tissue 10.8 weeks menstrual age. As shown in FIG. 16, ECSM4expression is highly specific for the vascular endothelial cells of theblood vessel in placenta. Furthermore, expression was absent throughouta number of other normal tissues that were analysed, including adultliver, brain cerebrum and large vessels, prostate, colon, small bowel,heart, eye (choroid and sclera), ovary, stomach, breast and foetalbladder, testis, kidney (15.8 weeks) and foetal heart, kidney, adrenal,intestine (11.3 weeks) foetal brain (10.6 weeks) and foetal eye (16.5weeks) (data not shown).

ISH analysis of colorectal liver metastasis biopsies showed thatexpression of ECSM4 was restricted to vascular endothelial cells of thetumour vessels only (FIGS. 17 and 18). No expression was detected in thesurrounding normal tissue. Furthermore the enhanced expression in thevicinity of the necrotic tissues (FIG. 18, necrotic tissue is indicatedby the bright signal labelled *) is indicative and consistent withinduction of ECSM4 expression by hypoxia. As such, ECSM4 may be a novelhypoxia regulated gene.

The highly restricted expression pattern of ECSM4 in angiogenic vesselsin normal and tumour tissues in adult is entirely consistent with theendothelial cell selective pattern of expression determined by the insilico analysis described in Example 1.

Methods

Blocks of formalin-fixed, paraffin-embedded tissues and tumours wereobtained from the archives of the Imperial Cancer Research Fund BreastPathology Group at Guys Hospital, London, UK. An antisense riboprobe toECSM4 cDNA was prepared for specific localisation of the ECSM4 mRNA byin situ hybridisation. The methods for pretreatment, hybridisation,washing, and dipping of slides in Ilford K5 for autoradiography has beendescribed previously (Poulsom, R., Longcroft, J. M., Jeffrey, R. E.,Rogers, L., and Steel, J. H. (1998) Eur. J. Histochem. 42, 121-132).Films were exposed for 7 to 15 days before developing in Kodak D19 andcounterstaining with Giemsa. Sections were examined under conventionalor reflected light dark-field conditions (Olympus BH2 withepi-illumination) under a ×5, ×10 or ×20 objective that allowedindividual auto-radiographic silver grains to be seen as bright objectson a dark background.

EXAMPLE 3

ECSM4 Polypeptide is Detected Only in Endothelial Cells.

Antibodies capable of selectively binding the ECSM4 polypeptide weregenerated and used in immunohistochemistry to demonstrate the presenceof ECSM4 polypeptide in a range of cell types (FIGS. 21 to 26). Tissuesamples were prepared by standard techniques in the art ofimmunohistochemistry.

Generation of Antibodies Recognising ECSM4.

The peptides MR 165, MR 311 and MR 336 were fused to Keyhole LimpetHaemocyanin (KLH) before immunisation of rabbits for production ofpolyclonal antibodies. The antibody MGO-5 was derived from rabbitsimmunised with the peptide MR 165, whereas MGO-7 was derived fromrabbits immunised with a mixture of MR 311 and MR 336. The sequence ofthe peptides used to generated the polyclonal antibodies is shown belowwith their reference within the amino acid sequence of full length humanECSM4 as shown in FIG. 12.

-   -   MR 165=LSQSPGAVPQALVAWRA (681-697) (SEQ ID NO:6)    -   MR 274=DSVLTPEEVALCLEL (790-804) (SEQ ID NO:7)    -   MR 311=TYGYISVPTA (827-836) (SEQ ID NO:8)    -   MR 336=KGGVLLCPPRPCLTPT (852-867) (SEQ ID NO:9)

EXAMPLE 4

The magic roundabout EST sequence identified in the bioinformaticssearch for endothelial specific transcripts was used to isolate a cDNAof 3800 base pairs in length from a human heart cDNA library. A screenusing gene specific primers showed the gene to be present in librariesfrom heart, adult and foetal brain, liver, lung, kidney, muscle,placenta and small intestine but absent from peripheral bloodleukocytes, spleen and testis. Highest expression was in the placentallibrary. Comparison of the magic roundabout sequence to that ofroundabout revealed a transmembrane protein with homology throughout butabsence of some extracellular domains. Thus, MR has two immunoglobulinand two fibronectin domains in the extracellular domain compared to fiveimmunoglobulin and two fibronectin domains in the extracellular domainsof the neuronal specific roundabouts. A transmembrane domain wasidentified by (i) using the transmembrane predicting software PRED-TMRand (ii) using an alignment between human MR and human ROBO1 peptidesequences. Both methods identified the same residues as thetransmembrane region of human MR as amino acids 468490. Thus, aa 1-467are extracellular and aa 491-1007 are intracellular. The intracellulardomain contains a putative proline rich region that is homologous tothose in roundabout that are thought to couple to c-abl (Bashaw et al(2000) Cell 101: 703-715).

Human SHGC-11739 (GenBank acc. G14646) sequence tagged site (STS) wasmapped to magic roundabout mRNA in a BLAST dbSTS search. This STSmaps tochromosome 11 on the Stanford G3 physical map (region 5647.00 cR10000LOD 1.09 bin 129). Nevertheless, much sequence is missing and thegenomic structure is not known. Search of the RIKEN database identifiedmurine magic roundabout. The predicted molecular weight for the peptidecore of human MR was 107,457 kDa. This was confirmed by in vitrotranslation (FIG. 3).

EXAMPLE 5

ECSM4 Expression is Detectable in Tumours

In situ hybridisation was used to characterise expression of ECSM4 invivo. Expression of ECSM4 was found to be very restricted (Table 13),with no signal detectable in many tissues including neuronal tissue. Incontrast, strong expression was detected in pacenta and a range oftumours including those of the brain, bladder and colonic metastasis tothe liver (FIG. 27). Expression within tumours was restricted to thetumour vasculature. Immuno-histochemical staining of placenta confirmedendothelial specific expression of the protein.

A search of CGAP SAGE libraries for ECSM4 detected it only inendothelial and tumour libraries (Table 14). This was consistent with insitu hybridisation results in the adult showing that expression wasrestricted to tumour vessels (colon metastasis to liver, ganglioglioma,bladder and breast carcinoma).

TABLE 13 Expression of magic roundabout in human tissue in vivo.Expression detected Placenta and umbilical cord foetal tissue (10.8weeks menstrual age) Vessels in colorectal liver metastasis,ganglioglioma, bladder and breast carcinoma. Expression not detectedAdult liver, brain cerebrum and large vessels, prostate, colon, smallbowel, heart, eye choroid and sclera, ovary, stomach, breast

TABLE 14 CGAP SAGE libraries in which magic roundabout was found on thebasis of gene to tag mapping Library Tags/million Tags HDMEC 171 HDMEC +VEGF 224 Medulloblastoma 102 Glioblastoma multiforme 85 Ovary, serousadenocarcinoma 59 Glioblastoma multiforme, pooled 48 HDMEC, human dermalmicrovascular endothelial cells; VEGF, vascular endothelial growthfactor.

EXAMPLE 6

Induction of ECSM4 in hypoxic endothelial cells

Initial RT-PCR Detected ECSM4 expression in endothelial but not othercell lines such as fibroblasts (normal endometial and FEK4), coloncarcinoma (SW480 and HCT116), breast carcinoma (MDA453 and MDA468) andHeLa cells. Ribonuclease protection analysis has confirmed and extendedthis (FIG. 11 a). ECSM4 expression was seen to be restricted toendothelium (three different isolates) and absent from fibroblast,carcinoma and neuronal cells. Induction of ECSM4 in hypoxia inendothelial (but not non-endothelial cells) was seen when expression ofECSM4 was analysed using two different RNase protection probes.Expression was on average 5.5 and 2.6 fold higher in hypoxia for HUVECand HDMEC respectively. Western analysis identified a weak band of 110kD in human dermal microvascular endothelial cells (HDMEC) but absentfrom the non-endothelial cells types (FIG. 11 b). The band was moreintense when the HDMEC cells were epxosed to 18 h hyposia, consistentwith ECSM4 being a hypoxically regulated gene.

1. A compound comprising (i) an antibody which selectively binds to apolypeptide having at least 90% identity to the amino acid sequence ofSEQ ID NO:37, and (ii) a further moiety, wherein the further moietycomprises a polypeptide, a directly cytotoxic chemotherapeutic agent, adirectly cytotoxic polypeptide, a cytotoxic moiety which is able toconvert a relatively non-toxic prodrug into a cytotoxic drug, or aradiosensitizer.
 2. A compound according to claim 1 wherein the furthermoiety is a directly cytotoxic chemotherapeutic agent.
 3. A compoundaccording to claim 1 wherein the further moiety is a directly cytotoxicpolypeptide.
 4. A compound according to claim 1 wherein the furthermoiety is a moiety which is able to convert a relatively non-toxicprodrug into a cytotoxic drug.
 5. A compound according to claim 1wherein the further moiety is a radiosensitizer.
 6. A compound accordingto claim 1 wherein the further moiety is able to bind to a directly orindirectly cytotoxic moiety.
 7. A compound according to claim 1 whereinthe further moiety is able to bind to a readily detectable moiety.
 8. Acompound according to claim 1 wherein the further moiety is apolypeptide which is fused to the antibody which selectively binds tothe polypeptide having at least 90% identity to the amino acid sequenceof SEQ ID NO:37.
 9. A kit comprising a compound according to claim 4 anda relatively non-toxic prodrug compared to the corresponding cytotoxicdrug.
 10. A kit comprising a compound according to claim 6 and adirectly or indirectly cytotoxic moiety to which the said compound isable to bind via its further moiety.
 11. A kit comprising a compoundaccording to claim 7 and a readily detectable moiety to which the saidcompound is able to bind via its further moiety.
 12. A compoundaccording to claim 1 wherein the antibody selectively binds to apolypeptide having at least 95% identity to the amino acid sequence ofSEQ ID NO:37.
 13. A compound according to claim 1 wherein the antibodyselectively binds to a polypeptide having at least 98% identity to theamino acid sequence of SEQ ID NO:37.
 14. A compound according to claim 1wherein the antibody selectively binds to a polypeptide comprising theamino acid sequence of SEQ ID NO:37.
 15. A compound comprising (i) anantibody which selectively binds to a polypeptide having at least 90%identity to the amino acid sequence of SEQ ID NO:37, and (ii) a furthermoiety, wherein the further moiety comprises a polypeptide, a directlycytotoxic chemotherapeutic agent, a directly cytotoxic polypeptide, acytotoxic moiety which is able to convert a relatively non-toxic prodruginto a cytotoxic drug, or a radiosensitizer, wherein the compound isused for treatment of cancer.
 16. A compound according to claim 15wherein the antibody selectively binds to the extracellular domain of apolypeptide having at least 90% identity to the amino acid secjuence ofSEQ ID NO:37.
 17. A pharmaceutical composition comprising a compoundcomprising (i) an antibody which selectively binds to a polypeptidehaving at least 90% identity to the amino acid sequence of SEQ ID NO:37,and (ii) a further moiety, wherein the further moiety comprises apolypeptide, a directly cytotoxic chemotherapeutic agent, a directlycytotoxic polypeptide, a cytotoxic moiety which is able to convert arelatively non-toxic prodrug into a cytotoxic drug, a radiosensitizer, aradioactive atom, a readily detectable radioactive atom, or a readilydetectable spin label.
 18. The pharmaceutical composition of claim 17wherein the antibody selectively binds to a polypeptide having at least95% identity to the amino acid sequence of SEQ ID NO:37.
 19. Thepharmaceutical composition of claim 17 wherein the antibody selectivelybinds to a polypeptide having at least 98% identity to the amino acidsequence of SEQ ID NO:37.
 20. The pharmaceutical composition of claim 17wherein the antibody selectively binds to a polypeptide comprising theamino acid sequence of SEQ ID NO:37.
 21. The pharmaceutical compositionof claim 17 wherein the antibody selectively binds to the extracellulardomain of a polypeptide having at least 90% identity to the amino acidsequence of SEQ ID NO:37.
 22. The pharmaceutical composition of claim 17wherein the further moiety is a directly cytotoxic chemotherapeuticagent.
 23. The pharmaceutical composition of claim 17 wherein thefurther moiety is a directly cytotoxic polypeptide.
 24. Thepharmaceutical composition of claim 17 wherein the further moiety is amoiety which is able to convert a relatively non-toxic prodrug into acytotoxic drug.
 25. The pharmaceutical composition of claim 17 whereinthe further moiety is a radiosensitizer.
 26. The pharmaceuticalcomposition of claim 17 wherein the further moiety comprises aradioactive atom.
 27. The pharmaceutical composition of claim 26 whereinthe radioactive atom is any one of phosphorus-32, iodine-125,iodine-131, indium-111, rhenium186, rhenium-188 or yttrium-90.
 28. Thepharmaceutical composition of claim 17 wherein the further moietycomprises a readily detectable radioactive atom.
 29. The pharmaceuticalcomposition of claim 28 wherein the readily detectable radioactive atomis selected from any one of technitium-99m or iodine-123.
 30. Thepharmaceutical composition of claim 17 wherein the readily detectablyspin label comprises a suitable amount of any one of iodine-123,iodine-131, indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17,gadolinium, manganese or iron.
 31. The pharmaceutical composition ofclaim 17 wherein the further moiety is able to bind to a directly orindirectly cytotoxic moiety.
 32. The pharmaceutical composition of claim17 wherein the further moiety is able to bind to a readily detectablemoiety.
 33. The pharmaceutical composition of claim 17 wherein thefurther moiety is a polypeptide which is fused to the antibody whichselectively binds to the polypeptide having at least 90% identity to theamino acid sequence of SEQ ID NO:37.